Question

If it took eight men ten hours to build a wall how long would it take four men to build it

Answer 1

Let the time taken by four men by x hrs.

No of people 8 4

Time taken 10 x

Note that less the no. of people, the more would be the time taken. Therefore, this is a case of inverse proportion.

So,

$8 \times 10= 4\times x \\ \frac{8 \times 10}{4} = x \\ 20 = x$

Thus, the time taken to build the wall by 4 men is 20 hours.

$\color{yellow}{hope \: it \: helps \: !!}$