Question

$90$ men can complete a work in $24$ days working $8$ hours a day. How many men are required to complete the same work in $18$ days working $7\frac{1}{2}$ hours a day?

Answer 1

Let word done be $W$

Work done in $1$ hr by $1$ worker $=\frac{W}{18\times 24\times 8}$

Let $x$ men work for $18$ days, for $\frac{15}{2}hrs.$

$\Rightarrow \frac{W}{18\times 24\times 8}\times x\times 18\times \frac{15}{2}=W$

$\Rightarrow x=\frac{18\times 24\times 8}{9\times 15}=25.6\simeq 26men.$

Hence, the answer is $25.6\simeq 26men.$