## RS Aggarwal Class 8 Solutions Chapter 12 Direct and Inverse Proportions Ex 12C

These Solutions are part of RS Aggarwal Solutions Class 8. Here we have given RS Aggarwal Solutions Class 8 Chapter 12 Direct and Inverse Proportions Ex 12C.

**Other Exercises**

- RS Aggarwal Solutions Class 8 Chapter 12 Direct and Inverse Proportions Ex 12A
- RS Aggarwal Solutions Class 8 Chapter 12 Direct and Inverse Proportions Ex 12B
- RS Aggarwal Solutions Class 8 Chapter 12 Direct and Inverse Proportions Ex 12C

**OBJECTIVE QUESTIONS :**

**Tick the correct answer in each of the following :**

**Question 1.**

**Solution:**

Answer = (d)

Cost of 14 kg of pulses = Rs 882

Cost of 1 kg of pulses Rs \(\\ \frac { 882 }{ 14 } \)

Cost of 22 kg of pulses = Rs \(\frac { 882\times 22 }{ 14 } \)

= 63 x 22

= Rs 1386

**Question 2.**

**Solution:**

Let x be oranges which can be bought for Rs. 33.80

8 : x : : 10.40 : 33.80

=> x × 10.40 = 8 x 33.80

=> \(\frac { 8\times 33.80 }{ 10.40 } \)

=> \(\frac { 8\times 3380 }{ 1040 } \)

= 26

∴ No. of oranges = 26 Ans. (c)

**Question 3.**

**Solution:**

No. of bottles 420 x

Time 3 5

More time, more bottles

By direct proportion

420 : x :: 3 : 5

x = \(\frac { 420\times 5 }{ 3 } \)

= 700

∴ No. of bottle will be 700 (b)

**Question 4.**

**Solution:**

Distance covered 75 km x

Time taken 60 min. 20 min.

Less time, less distance By direct proportion,

75 : x :: 60 : 20

x = \(\frac { 75\times 20 }{ 60 } \)

= 25

∴ Distance covered = 25 km (a)

**Question 5.**

**Solution:**

No. of sheets 12 : x

Weight 40 g : 1000 g

More weight, more sheets

By direct proportion 12 : x :: 40 : 1000

x = \(\frac { 12\times 1000 }{ 40 } \)

= 300

∴ No. of sheets = 300 (c)

**Question 6.**

**Solution:**

Let x be the height of tree

Height of pole 14 m : x m

Length of shadow 10 m : 7 m

Less shadow, less height

By direct proportion 14 : x :: 10 : 7

x = \(\frac { 14\times 7 }{ 10 } \)

= \(\\ \frac { 98 }{ 10 } \)

= 9.8 m

∴ Height of the = 9.8 m (b)

**Question 7.**

**Solution:**

Let actual length of bacteria = x cm

Enlarged (times) 50000

Length 5 cm

Then actual length (x)

Then \(\frac { x\times 50000 }{ -4 } \)

= 5

=> x = \(\\ \frac { 5 }{ 50000 } \)

= \(\\ \frac { 1 }{ 10000 } \)

= 10 cm (c)

**Question 8.**

**Solution:**

No. of pipes 6 : 5

Time taken to 120 min : x min

fill the tank

Less pipes, more time

By inverse proportion 6 : 5 :: x : 120

x = \(\frac { 6\times 120 }{ 5 } \)

= 144 (b)

∴ Time taken = 144 minutes

**Question 9.**

**Solution:**

Let number of days = x, then

Persons 3 : 4

(Time taken to build a wall) 4 : x

More person, less time take

By inverse proportion,

3 : 4 :: x : 4

x = \(\frac { 4\times 3 }{ 4 } \)

= 3 (b)

∴ Time taken to build the wall = 3 days

**Question 10.**

**Solution:**

Let time taken will be x hrs

Speed 60 km/h : 80 km/h

Time taken to 2hr : x

reach

(More speed, less time)

By inverse proportion 60 : 80 :: x : 2

x = \(\frac { 60\times 2 }{ 80 } \)

= \(\\ \frac { 3 }{ 2 } \)

∴ Time take \(\\ \frac { 3 }{ 2 } \) hours or 1 hr. 30 m in. (a)

Hope given RS Aggarwal Solutions Class 8 Chapter 12 Direct and Inverse Proportions Ex 12C are helpful to complete your math homework.

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