Question

If $20$men can build a wall $56m$long in $6$days, what length of a similar wall can be built by $35$ men in$3$ days?

Answer 1

Wall built by $20$ men in $6$ days $=50$

$\Rightarrow$ Wall built by $1$ men in $1$ day $=\frac{50}{20\times 6}=\frac{50}{120}$

$\Rightarrow$ Wall built by $35$ men in $3$ days $=\frac{50\times 35\times 3}{120}$

$=\frac{50\times 35}{40}$

$=\frac{50\times 7}{8}$

$=49m.$

Hence, the answer is $49m.$