If $20$ workers can build a wall $30$ m long in $25$ days, how many workers are needed to build a similar wall $48$ m long in $20$ days?

Question

Aicharya · Accepted Answer

Workers $\propto$ length (direct) and $\propto \dfrac{1}{	ext{days}}$ (inverse). $w = 20 	imes \dfrac{48}{30} 	imes \dfrac{25}{20} = 20 	imes \dfrac{48 	imes 25}{30 	imes 20} = 20 	imes 2 = 40$.

If $20$ workers can build a wall $30$ m long in $25$ days, how many workers are needed to build a similar…

Solution