ICSE

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 5 Playing with Number

Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 5 Playing with Number

Playing with Number Exercise 5A – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Write the quotient when the sum of 73 and 37 is divided by
(i) 11
(ii) 10
Solution:

Question 2.
Write the quotient when the sum of 94 and 49 is divided by
(i) 11
(ii) 13
Solution:

Question 3.
Find the quotient when 73 – 37 is divided by
(i) 9
(ii) 4
Solution:

Question 4.
Find the quotient when 94 – 49 is divided by
(i) 9
(ii) 5
Solution:

Question 5.
Show that 527 + 752 + 275 is exactly divisible by 14.
Solution:

Question 6.
If a = 6, show that abc = bac.
Solution:

Question 7.
If a > c; show that abc – cba = 99(a – c).
Solution:

Question 8.
If c > a; show that cba – abc = 99(c – a).
Solution:

Question 9.
If a = c, show that cba – abc = 0.
Solution:

Question 10.
Show that 954 – 459 is exactly divisible by 99.
Solution:

Playing with Number Exercise 5B – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.

Solution:

Question 2.

Solution:

Question 3.

Solution:

Question 4.

Solution:

Question 5.

Solution:

Question 6.

Solution:

Question 7.

Solution:

Question 8.

Solution:

Question 9.

Solution:

Question 10.

Solution:

Question 11.

Solution:

Playing with Number Exercise 5C – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Find which of the following nutpbers are divisible by 2:
(i) 192
(ii) 1660
(iii) 1101
(iv) 2079
Solution:

Question 2.
Find which of the following numbers are divisible by 3:
(i) 261
(ii) 111
(iii) 6657
(iv) 2574
Solution:

Question 3.
Find which of the following numbers are divisible by 4:
(i) 360
(ii) 3180
(iii) 5348
(iv) 7756
Solution:

Question 4.
Find which of the following numbers are divisible by 5 :
(i) 3250
(ii) 5557
(iii) 39255
(iv) 8204
Solution:

Question 5.
Find which of the following numbers are divisible by 10:
(i) 5100
(ii) 4612
(iii) 3400
(iv) 8399
Solution:

Question 6.
Which of the following numbers are divisible by 11 :
(i) 2563
(ii) 8307
(iii) 95635
Solution:

Playing with Number Exercise 5D – Selina Concise Mathematics Class 8 ICSE Solutions

For what value of digit x, is :
Question 1.
1×5 divisible by 3?
Solution:

Question 2.
31×5 divisible by 3?
Solution:

Question 3.
28×6 a multiple of 3?
Solution:

Question 4.
24x divisible by 6 ?
Solution:

Question 5.
3×26 a multiple of 6?
Solution:

Question 6.
42×8 divisible by 4?
Solution:

Question 7.
9142x a multiple of 4?
Solution:

Question 8.
7×34 divisible by 9?
Solution:

Question 9.
5×555 a multiple of 9 ?
Solution:

Question 10.
3x² divisible by 11?
Solution:

Question 11.
5x² a multiple of 11?
Solution:

Selina Concise Mathematics Class 8 ICSE Solutions

Selina Concise Mathematics Class 7 ICSE Solutions Chapter 13 Set Concepts (Some Simple Divisions by Vedic Method)

Selina Publishers Concise Mathematics Class 7 ICSE Solutions Chapter 13 Set Concepts (Some Simple Divisions by Vedic Method)

Set Concepts Exercise 13A – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
Find, whether or not, each of the following collections represent a set:
(i) The collection of good students in your school.
(ii) The collection of the numbers between 30 and 45.
(iii) The collection of fat-people in your colony.
(iv) The collection of interesting books in your school library.
(v) The collection of books in the library and are of your interest.
Solution:

Question 2.
State whether true or false :
(i) Set {4, 5, 8} is same as the set {5, 4, 8} and the set {8, 4, 5}
(ii) Sets {a, b, m, n} and {a, a, m, b, n, n) are same.
(iii) Set of letters in the word ‘suchismita’ is {s, u, c, h, i, m, t, a}
(iv) Set of letters in the word ‘MAHMOOD’ is {M, A, H, O, D}.
Solution:

Question 3.
Let set A = {6, 8, 10, 12} and set B = {3, 9, 15, 18}.
Insert the symbol ‘ ∈ ’ or ‘ ∉ ’ to make each of the following true :
(i) 6 …. A
(ii) 10 …. B
(iii) 18 …. B
(iv) (6 + 3) …. B
(v) (15 – 9) …. B
(vi) 12 …. A
(vii) (6 + 8) …. A
(viii) 6 and 8 …. A
Solution:

Question 4.
Express each of the following sets in
roster form :
(i) Set of odd whole numbers between 15 and 27.
(ii) A = Set of letters in the word “CHITAMBARAM”
(iii) B = {All even numbers from 15 to 26}
(iv) P = {x : x is a vowel used in the word ‘ARITHMETIC’}
(v) S = {Squares of first eight whole numbers}
(vi) Set of all integers between 7 and 94; which are divisible by 6.
(vii) C = {All composite numbers between 2 and 20}
(viii) D = Set of Prime numbers from 2 to 23.
(ix) E = Set of natural numbers below 30 which are divisible by 2 or 5.
(x) F = Set of factors of 24.
(xi) G = Set of names of three closed figures in Geometry.
(xii) H = {x : x eW and x < 10}
(xiii) J = {x: x e N and 2x – 3 ≤17}
(xiv) K = {x : x is an integer and – 3 < x < 5}
Solution:

Question 5.
Express each of the following sets in set- builder notation (form) :
(i) {3, 6, 9, 12, 15}
(ii) {2, 3, 5, 7, 11, 13 …. }
(iii) {1, 4, 9, 16, 25, 36}
(iv) {0, 2, 4, 6, 8, 10, 12, …. }
(v) {Monday, Tuesday, Wednesday}
(vi) {23, 25, 27, 29, … }
(vii) {\(\frac { 1 }{ 3 }\),\(\frac { 1 }{ 4 }\),\(\frac { 1 }{ 5 }\),\(\frac { 1 }{ 6 }\),\(\frac { 1 }{ 7 }\),\(\frac { 1 }{ 8 }\)}
(viii) {42, 49, 56, 63, 70, 77}
Solution:

Question 6.
Given : A = {x : x is a multiple of 2 and is less than 25}
B = {x : x is a square of a natural number and is less than 25}
C = {x : x is a multiple of 3 and is less than 25}
D = {x: x is a prime number less than 25}
Write the sets A, B, C and D in roster form.
Solution:

Set Concepts Exercise 13B – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
Write the cardinal number of each of the following sets:
(i) A = Set of days in a leap year.
(ii) B = Set of numbers on a clopk-face.
(iii) C = {x : x ∈ N and x ≤ 7}
(iv) D = Set of letters in the word “PANIPAT”.
(v) E = Set of prime numbers between 5 and 15.
(vi) F = {x : x ∈ Z and – 2 < x ≤ 5}
(vii) G = {x : x is a perfect square number, x ∈N and x ≤ 30}.
Solution:

Question 2.
For each set, given below, state whether it is finite set, infinite set or the null set :
(i) {natural numbers more than 100}
(ii) A = {x : x is an integer between 1 and 2}
(iii) B = {x : x ∈ W ; x is less than 100}.
(iv) Set of mountains in the world.
(v) {multiples of 8}.
(vi) {even numbers not divisible by 2}.
(vii) {squares of natural numbers}.
(viii) {coins used in India}
(ix) C = {x | x is a prime number between 7 and 10}.
(x) Planets of the Solar system.
Solution:

Question 3.
State, which of the following pairs of sets are disjoint :
(i) {0, 1, 2, 6, 8} and {odd numbers less than 10.
(ii) {birds} and {tress}
(iii) {x : x is a fan of cricket} and {x : x is a fan of football}.
(iv) A = {natural numbers less than 10} and B = {x : x is a multiple of 5}.
(v) {people living in Calcutta} and {people living in West Bengal}.
Solution:

Question 4.
State whether the given pairs of sets are equal or equivalent.
(i) A = {first four natural numbers} and B = {first four whole numbers}.
(ii) A = Set of letters of the word “FOLLOW” and B = Set of letters of the word “WOLF”.
(iii) E = {even natural numbers less than 10} and O = {odd natural numbers less than 9}
(iv) A = {days of the week starting with letter S} and B = {days of the week starting with letter T}.
(v) M = {multiples of 2 and 3 between 10 and 20} and N = {multiples of 2 and 5 between 10 and 20}.
(vi) P = {prime numbers which divide 70 exactly} and Q = {prime numbers which divide 105 exactly}
(vii) A = {0², 1², 2², 3², 4²} and = {16, 9,4, 1, 0}.
(viii) E = {8,JO, 12, 14, 16} and F = {even natural numbers between 6 and 18}.
(ix) A = {letters of the word SUPERSTITION} and B = {letters of the word JURISDICTION}.
Solution:

Question 5.
Examine which of the following sets are the empty sets :
(i) The set of triangles having three equal sides.
(ii) The set of lions in your class.
(iii) {x : x + 3 = 2 and xeN}
(iv) P = {x : 3x = 0}
Solution:

Question 6.
State true or false :
(i) All examples of the empty set are equal.
(ii) All examples of the empty set are equivalent.
(iii) If two sets have the same cardinal number, they are equal sets.
(iv) If n (A) = n (B) then A and B are equivalent sets.
(v) If B = {x : x + 4 = 4}, then B is the empty set.
(vi) The set of all points in a line is a finite set.
(vii) The set of letters in your Mathematics book is an infinite set.
(viii) If M = {1, 2, 4, 6} and N = {x : x is a factor of 12} ; then M = N.
(ix) The set of whole numbers greater than 50 is an infinite set.
(x) If A and B are two different infinite sets, then n (A) = n (B).
Solution:

Question 7.
Which of the following represent the null set ?
φ, {0}, 0, { }, {φ}
Solution:

Set Concepts Exercise 13C – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
Fill in the blanks :
(i) If each element of set P is also an element of set Q, then P is said to be …… of Q and Q is said to be of P.
(ii) Every set is a ….. of itself.
(iii) The empty set is a …… of every set.
(iv) If A is proper subset of B, then n (A) …. n (B).
Solution:

Question 2.
If A = {5, 7, 8, 9} ; then which of the following are subsets of A ?
(i) B = {5, 8}
(ii) C = {0}
(iii) D = {7, 9, 10}
(iv) E = { }
(V) F = {8, 7, 9, 5}
Solution:

Question 3.
If P = {2, 3, 4, 5} ; then which of the following are proper subsets of P ?
(i) A = {3, 4}
(ii) B = { }
(iii) C = {23, 45}
(iv) D = {6, 5, 4}
(v) E = {0}
Solution:

Question 4.
If A = {even numbers less than 12},
B = {2, 4},
C = {1, 2, 3},
D = {2, 6} and E = {4}
State which of the following statements are true :
(i) B⊂A
(ii) C⊆A
(iii) D⊂C
(iv) D ⊄ A
(v)E⊇B
(vi) A⊇B⊇E
Solution:

Question 5.
Given A = {a, c}, B = {p, q, r} and C = Set of digits used to form number 1351.
Write all the subsets of sets A, B and C.
Solution:

Question 6.
(i) If A = {p, q, r}, then number of subsets of A = ……
(ii) If B = {5, 4, 6, 8}, then number of proper subsets of B = ……
(iii) If C = {0}, then number of subsets of C = …..
(iv) If M = {x : x ∈ N and x < 3}, then M has …… proper subsets.
Solution:

Question 7.
For the universal set {4, 5, 6, 7, 8, 9, 10, 11,12,13} ; find its subsets A, B, C and D such that
(i) A = {even numbers}
(ii) B = {odd numbers greater than 8}
(iii) C = {prime numbers}
(iv) D = {even numbers less than 10}.
Also, find compliments of each set i.e., find A’, B’, C’ and D’.
Solution:

Set Concepts Exercise 13D – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
If A = {4, 5, 6, 7, 8} and B = {6, 8, 10, 12}, find :
(i) A∪B
(ii) A∩B
(iii) A-B
(iv) B-A
Solution:

Question 2.
If A = {3, 5, 7, 9, 11} and B = {4, 7, 10}, find:
(i) n(A)
(ii) n(B)
(iii) A∪B and n(A∪B)
(iv) A∩B and n(A∩B)
Solution:

Question 3.
If A = {2, 4, 6, 8} and B = {3, 6, 9, 12}, find:
(i) (A ∩ B) and n(A ∩ B)
(ii) (A – B) and n(A – B)
(iii) n(B)
Solution:

Question 4.
If P = {x : x is a factor of 12} and Q = {x: x is a factor of 16}, find :
(i) n(P)
(ii) n(Q)
(iii) Q – P and n(Q – P)
Solution:

Question 5.
M = {x : x is a natural number between 0 and 8) and N = {x : x is a natural number from 5 to 10}. Find :
(i) M – N and n(M – N)
(ii) N – M and n(N – M)
Solution:

Question 6.
If A = {x: x is natural number divisible by 2 and x< 16} and B = {x:x is a whole number divisible by 3 and x < 18}, find :
(i) n(A)
(ii) n(B)
(iii) A∩B and n(A∩B)
(iv) n(A – B)
Solution:

Question 7.
Let A and B be two sets such that n(A) = 75, M(B) = 65 and n(A ∩ B) = 45, find :
(i) n(A∪ B)
(ii) n(A – B)
(iii) n(B – A)
Solution:

Question 8.
Let A and B be two sets such that n(A) = 45, n(B) = 38 and n(A ∪B) = 70, find :
(i) n(A∩B)
(ii) n(A-B)
(iii) n(B – A)
Solution:

Question 9.
Let n(A) 30, n(B) = 27 and n(A∪B) = 45, find :
(i) n(A∩B)
(ii) n(A-B)
Solution:

Question 10.
Let n(A) = 31, n(B) = 20 and n(A ∩ B) = 6, find:
(i) n(A-B)
(ii) n(B – A)
(iii) n(A ∪B)
Solution:

Selina Concise Mathematics Class 7 ICSE Solutions

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 4 Cubes and Cube-Roots (Including use of tables for natural numbers)

Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 4 Cubes and Cube-Roots (Including use of tables for natural numbers)

Cubes and Cube-Roots Exercise 4A – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Find the cube of :
(i) 7
(ii) 11
(iii) 16
(iv) 23
(v) 31
(vi) 42
(vii) 54
Solution:

Question 2.
Find which of the following are perfect cubes :
(i) 243
(ii) 588
(iii) 1331
(iv) 24000
(v) 1728
(vi) 1938
Solution:

Question 3.
Find the cubes of :
(i) 2.1
(ii) 0.4
(iii) 1.6
(iv) 2.5
(v) 0.12
(vi) 0.02
(vii) 0.8
Solution:

Question 4.
Find the cubes of :
(i) \(\frac { 3 }{ 7 }\)
(ii) \(\frac { 8 }{ 9 }\)
(iii) \(\frac { 10 }{ 13 }\)
(iv) \(1\frac { 2 }{ 7 }\)
(v) \(2\frac { 1 }{ 2 }\)
Solution:

Question 5.
Find the cubes of :
(i) -3
(ii) -7
(iii) -12
(iv) -18
(v) -25
(vi) -30
(vii) -50
Solution:

Question 6.
Which of the following are cubes of:
(i) an even number
(ii) an odd number
216, 729, 3375, 8000, 125, 343, 4096 and 9261.
Solution:

Question 7.
Find the least number by which 1323 must be multiplied so that the product is a perfect cube.
Solution:

Question 8.
Find the smallest number by which 8768 must be divided so that the quotient is a perfect cube.
Solution:

Question 9.
Find the smallest number by which 27783 be multiplied to get a perfect square number.
Solution:

Question 10.
With what least number must 8640 be divided so that the quotient is a perfect cube?
Solution:

Question 11.
Which is the smallest number that must be multiplied to 77175 to make it a perfect cube?
Solution:

Cubes and Cube-Roots Exercise 4B – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Find the cube-roots of :
(i) 64
(ii) 343
(iii) 729
(iv) 1728
(v) 9261
(vi) 4096
(vii) 8000
(viii) 3375
Solution:

Question 2.
Find the cube-roots of :
(i) \(\frac { 27 }{ 64 }\)
(ii) \(\frac { 125 }{ 216 }\)
(iii) \(\frac { 343 }{ 512 }\)
(iv) 64 x 729
(v) 64 x 27
(vi) 729 x 8000
(vii) 3375 x 512
Solution:

Question 3.
Find the cube-roots of :
(i) -216
(ii) -512
(iii) -1331
(iv) \(\frac { -27 }{ 125 }\)
(v) \(\frac { -64 }{ 343 }\)
(vi) \(\frac { -512 }{ 343 }\)
(vii) -2197
(viii) -5832
(ix) -2744000
Solution:

Question 4.
Find the cube-roots of :
(i) 2.744
(ii) 9.261
(iii) 0.000027
(iv) -0.512
(v) -15.625
(vi) -125 x 1000
Solution:

Question 5.
Find the smallest number by which 26244 may be divided so that the quotient is a perfect cube.
Solution:

Question 6.
What is the least number by which 30375 should be multiplied to get a perfect cube?
Solution:

Question 7.
Find the cube-roots of :
(i) 700 x 2 x 49 x 5
(ii) -216 x 1728
(iii) -64 x -125
(iv) \(\frac { -27 }{ 343 }\)
(v) \(\frac { 729 }{ -1331 }\)
(vi) 250.047
(vii) -175616
Solution:

Selina Concise Mathematics Class 8 ICSE Solutions

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 3 Squares and Square Roots

Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 3 Squares and Square Roots

Squares and Square Roots Exercise 3A – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Find the square of :
(i) 59
(ii) 63
(iii) 15
Solution:

Question 2.
By splitting into prime factors, find the square root of :
(i) 11025
(ii) 396900
(iii) 194481
Solution:

Question 3.
(i) Find the smallest number by which 2592 be multiplied so that the product is a perfect square.
(ii) Find the smallest number by which 12748 be multiplied so that the product is a perfect square?
Solution:
</span

Question 4.
Find the smallest number by which 10368 be divided, so that the result is a perfect square. Also, find the square root of the resulting numbers.
Solution:

Question 5.
Find the square root of :
(i) 0.1764
(ii) \(96\frac { 1 }{ 25 }\)
(iii) 0.0169
Solution:

Question 6.
Evaluate

Solution:

Question 7.

Solution:

Question 8.
A man, after a tour, finds that he had spent every day as many rupees as the number of days he had been on tour. How long did his tour last, if he had spent in all ₹ 1,296
Solution:

Question 9.
Out of 745 students, maximum are to be arranged in the school field for a P.T. display, such that the number of rows is equal to the number of columns. Find the number of rows if 16 students were left out after the arrangement.
Solution:

Question 10.
13 and 31 is a strange pair of numbers such that their squares 169 and 961 are also mirror images of each other. Find two more such pairs.
Solution:

Question 11.
Find the smallest perfect square divisible by 3, 4, 5 and 6.
Solution:

Question 12.
If √784 = 28, find the value of:
(i) √7.84 + √78400
(ii) √0.0784 + √0.000784
Solution:

Squares and Square Roots Exercise 3B – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Find the square root of:
(i) 4761
(ii) 7744
(iii) 15129
(iv) 0.2916
(v) 0.001225
(vi) 0.023104
(vii) 27.3529
Solution:

Question 2.
Find the square root of:
(i) 4.2025
(ii) 531.7636
(iii) 0.007225
Solution:

Question 3.
Find the square root of:
(i) 245 correct to two places of decimal.
(ii) 496 correct to three places of decimal.
(iii) 82.6 correct to two places of decimal.
(iv) 0.065 correct to three places of decimal.
(v) 5.2005 correct to two places of decimal.
(vi) 0.602 correct to two places of decimal
Solution:

Question 4.
Find the square root of each of the following correct to two decimal places:
(i) \(3\frac { 4 }{ 5 }\)
(ii) \(6\frac { 7 }{ 8 }\)
Solution:

Question 5.
For each of the following, find the least number that must be subtracted so that the resulting number is a perfect square.
(i) 796
(ii) 1886
(iii) 23497
Solution:

Question 6.
For each of the following, find the least number that must be added so that the resulting number is a perfect square.
(i) 511
(ii) 7172
(iii) 55078
Solution:

Question 7.
Find the square root of 7 correct to two decimal places; then use it to find the value of \(\sqrt { \frac { 4+\sqrt { 7 } }{ 4-\sqrt { 7 } } }\) correct to three significant digits.
Solution:

Question 8.
Find the value of √5 correct to 2 decimal places; then use it to find the square root of \(\sqrt { \frac { 3-\sqrt { 5 } }{ 3+\sqrt { 5 } } }\) correct to 2 significant digits.
Solution:

Question 9.
Find the square root of:
(i) \(\frac { 1764 }{ 2809 }\)
(ii) \(\frac { 507 }{ 4107 }\)
(iii) \(\sqrt { 108\times 2028 }\)
(iv) 0.01 + √0.0064
Solution:

Question 10.
Find the square root of 7.832 correct to :
(i) 2 decimal places
(ii) 2 significant digits.
Solution:

Question 11.
Find the least number which must be subtracted from 1205 so that the resulting number is a perfect square.
Solution:

Question 12.
Find the least number which must be added to 1205 so that the resulting number is a perfect square.
Solution:

Question 13.
Find the least number which must be subtracted from 2037 so that the resulting number is a perfect square.
Solution:

Question 14.
Find the least number which must be added to 5483 so that the resulting number is a perfect square.
Solution:

Squares and Square Roots Exercise 3C – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Seeing the value of the digit at unit’s place, state which of the following can be square of a number :
(i) 3051
(ii) 2332
(iii) 5684
(iv) 6908
(v) 50699
Solution:

Question 2.
Squares of which of the following numbers will have 1 (one) at their unit’s place :
(i) 57
(ii) 81
(iii) 139
(iv) 73
(v) 64
Solution:

Question 3.
Which of the following numbers will not have 1 (one) at their unit’s place :
(i) 322
(ii) 572
(iii) 692
(iv) 3212
(v) 2652
Solution:

Question 4.
Square of which of the following numbers will not have 6 at their unit’s place :
(i) 35
(ii) 23
(iii) 64
(iv) 76
(v) 98
Solution:

Question 5.
Which of the following numbers will have 6 at their unit’s place :
(i) 262
(ii) 492
(iii) 342
(iv) 432
(v) 2442
Solution:

Question 6.
If a number ends with 3 zeroes, how many zeroes will its square have?
Solution:

Question 7.
If the square of a number ends with 10 zeroes, how many zeroes will the number have?
Solution:

Question 8.
Is it possible for the square of a number to end with 5 zeroes ? Give reason.
Solution:

Question 9.
Give reason to show that none of the numbers, given below, is a perfect square.
(i) 2162
(ii) 6843
(iii) 9637
(iv) 6598
Solution:

Question 10.
State, whether the square of the following numbers is even or odd?
(i) 23
(ii) 54
(iii) 76
(iv) 75
Solution:

Question 11.
Give reason to show that none of the numbers 640, 81000 and 3600000 is a perfect square.
Solution:

Question 12.
Evaluate:
(i) 37² – 36²
(ii) 85² – 84²
(iii) 101² – 100²
Solution:

Question 13.
Without doing the actual addition, find the sum of:
(i) 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 + 21 + 23
(ii) 1 + 3 + 5 + 7 + 9 + ……………… + 39 + 41
(iii) 1 + 3 + 5 + 7 + 9 + ………………… + 51 + 53
Solution:

Question 14.
Write three sets of Pythagorean triplets such that each set has numbers less than 30.
Solution:

Selina Concise Mathematics Class 8 ICSE Solutions

Selina Concise Mathematics Class 7 ICSE Solutions Chapter 12 Simple Linear Equations (Including Word Problems)

Selina Publishers Concise Mathematics Class 7 ICSE Solutions Chapter 12 Simple Linear Equations (Including Word Problems)

Simple Linear Equations Exercise 12A – Selina Concise Mathematics Class 7 ICSE Solutions

Solve the following equations :

Question 1.
x + 5 = 10
Solution:

Question 2.
2 + y = 7
Solution:

Question 3.
a – 2 = 6
Solution:

Question 4.
x – 5 = 8
Solution:

Question 5.
5 – d= 12
Solution:

Question 6.
3p = 12
Solution:

Question 7.
14 = 7m
Solution:

Question 8.
2x = 0
Solution:

Question 9.
\(\frac { x }{ 9 }\) = 2
Solution:

Question 10.
\(\frac { y }{ -12 }\) = -4
Solution:

Question 11.
8x-2 =38
Solution:

Question 12.
2x + 5 = 5
Solution:

Question 13.
5x – 1 = 74
Solution:

Question 14.
14 = 27-x
Solution:

Question 15.
10 + 6a = 40
Solution:

Question 16.

Solution:

Question 17.

Solution:

Question 18.
12 = c – 2
Solution:

Question 19.
4 = x- 2.5
Solution:

Question 20.

Solution:

Question 21.

Solution:

Question 22.
p + 0.02 = 0.08

Solution:

Question 23.

Solution:

Question 24.

Solution:

Question 25.
1.3b = 39
Solution:

Question 26.

Solution:

Question 27.

Solution:

Question 28.
2a – 3 =5
Solution:

Question 29.
3p – 1 = 8
Solution:

Question 30.
9y -7 = 20
Solution:

Question 31.
2b – 14 = 8
Solution:

Question 32.

Solution:

Question 33.

Solution:

Simple Linear Equations Exercise 12B – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
8y – 4y = 20
Solution:

Question 2.
9b – 4b + 3b = 16
Solution:

Question 3.
5y + 8 = 8y – 18
Solution:

Question 4.
6 = 7 + 2p -5
Solution:

Question 5.
8 – 7x = 13x + 8
Solution:

Question 6.
4x – 5x + 2x  = 28 + 3x
Solution:

Question 7.
9 + m = 6m + 8 – m
Solution:

Question 8.
24 = y + 2y + 3 + 4y
Solution:

Question 9.
19x -+ 13 -12x + 3 = 23
Solution:

Question 10.
6b + 40 = – 100 – b
Solution:

Question 11.
6 – 5m – 1 + 3m = 0
Solution:

Question 12.
0.4x – 1.2  = 0.3x + 0.6
Solution:

Question 13.
6(x+4) = 36
Solution:

Question 14.
9 ( a+ 5) + 2 = 11
Solution:

Question 15.
4 ( x- 2 ) = 12
Solution:

Question 16.
-3 (a- 6 ) = 24
Solution:

Question 17.
7 ( x-2) = 2 (2x -4)
Solution:

Question 18.
(x-4) (2x +3 ) = 2x²
Solution:

Question 19.
21 – 3 ( b-7 ) = b+ 20
Solution:

Question 20.
x (x +5 ) = x² +x + 32
Solution:

Simple Linear Equations Exercise 12C – Selina Concise Mathematics Class 7 ICSE Solutions

Solve
Question 1.

Solution:

Question 2.

Solution:

Question 3.

Solution:

Question 4.

Solution:

Question 5.

Solution:

Question 6.

Solution:

Question 7.

Solution:

Question 8.

Solution:

Question 9.

Solution:

Question 10.

Solution:

Question 11.

Solution:

Question 12.
0.6a +0.2a = 0.4 a +8
Solution:

Question 13.
p + 1.4p= 48
Solution:

Question 14.
10% of x = 20
Solution:

Question 15.
y + 20% of y = 18
Solution:

Question 16.
x – 13% of x = 35
Solution:

Question 17.

Solution:

Question 18.

Solution:

Question 19.

Solution:

Question 20.

Solution:

Question 21.

Solution:

Question 22.

Solution:

Question 23.
15 – 2 (5-3x ) = 4 ( x-3 ) + 13
Solution:

Question 24.

Solution:

Question 25.
21 – 3 (x – 7) = x + 20
Solution:

Question 26.

Solution:

Question 27.

Solution:

Question 28.

Solution:

Question 29.

Solution:

Question 30.
2x + 20% of x = 12.1
Solution:

Simple Linear Equations Exercise 12D – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
One-fifth of a number is 5, find the number.
Solution:

Question 2.
Six times a number is 72, find the number.
Solution:

Question 3.
If 15 is added to a number, the result is 69, find the number.
Solution:

Question 4.
The sum of twice a number and 4 is 80, find the number.
Solution:

Question 5.
The difference between a number and one- fourth of itself is 24, find the number.
Solution:

Question 6.
Find a number whose one-third part exceeds its one-fifth part by 20.
Solution:

Question 7.
A number is as much greater than 35 as is less than 53. Find the number.
Solution:

Question 8.
The sum of two numbers is 18. If one is twice the other, find the numbers.
Solution:

Question 9.
A number is 15 more than the other. The sum of of the two numbers is 195. Find the numbers.
Solution:

Question 10.
The sum of three consecutive even numbers is 54. Find the numbers.
Solution:

Question 11.
The sum of three consecutive odd numbers is 63. Find the numbers.
Solution:

Question 12.
A man has ₹ x from which he spends ₹6. If twice of the money left with him is ₹86, find x.
Solution:

Question 13.
A man is four times as old as his son. After 20 years, he will be twice as old as his son at that time. Find their present ages.
Solution:

Question 14.
If 5 is subtracted from three times a number, the result is 16. Find the number.
Solution:

Question 15.
Find three consecutive natural numbers such that the sum of the first and the second is 15 more than the third.
Solution:

Question 16.
The difference between two numbers is 7. Six times the smaller plus the larger is 77. Find the numbers.
Solution:

Question 17.
The length of a rectangular plot exceeds its breadth by 5 metre. If the perimeter of the plot is 142 metres, find the length and the breadth of the plot.
Solution:

Question 18.
The numerator of a fraction is four less than its denominator. If 1 is added to both, is numerator and denominator, the fraction becomes \(\frac { 1 }{ 2 }\) Find the fraction.
Solution:

Question 19.
A man is thrice as old as his son. After 12 years, he will be twice as old as his son at that time. Find their present ages.
Solution:

Question 20.
A sum of ₹ 500 is in the form of notes of denominations of ₹ 5 and₹ 10. If the total number of notes is 90, find the number of notes of each type.
Solution:

Selina Concise Mathematics Class 7 ICSE Solutions