Direct and Inverse Proportion — Practice

Question 1

If 6 m of cloth cost ₹450, find the cost of 10 m.

Accepted Answer

1 m = 75; 10 m = ₹750.

Question 2

A car travels 240 km on 16 litres. How far on 6 litres?

Accepted Answer

1 litre = 15 km; 6 litres = 90 km.

Question 3

15 workers build a wall in 8 days. How many days for 10 workers?

Accepted Answer

15 × 8 = 10 × d → d = 12 days.

Question 4

If 9 pipes fill a tank in 20 minutes, how long for 12 pipes?

Accepted Answer

9 × 20 = 12 × t → t = 15 minutes.

Question 5

Is the number of workers and the time to finish a job direct or inverse?

Accepted Answer

Inverse proportion.

Question 6

Find x: 4 : 6 = x : 18.

Accepted Answer

4 × 18 = 6x → x = 12.

Practice — Direct and Inverse Proportion