Question

If 15 workers can build a wall in 48 hours, how many workers will be required to do the same work in 30 hours?

Answer 1

Let the number of workers employed to build the wall in 30 hours be y.

Number of hours	48	30
Number of workers	15	y

Obviously more the number of workers, the faster will they build the wall.

So, the number of hours and number of workers vary in inverse proportion.

So 48 × 15 = 30 × y

Therefore, `(48 xx 15)/30 = y`

y = 24

i.e., to finish the work in 30 hours, 24 workers are required.