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?

• A. 12
• B. 96
• C. 48
• D. 24

Answer 1

The correct option is D 24

Let the number of workers employed to build the wall in 30 hours be $y$.
We have the following table.

Number of hours	48	30
Number of workers	15	$y$

Obviously more the number of workers, faster will they build the wall.
So, the number of hours and number of workers vary in inverse proportion.
So, $48\times 15=30\times y$
⇒ $y=\frac{48\times 15}{30}=24$

Hence, $24$ workers are required to finish the work in $30$ hours.