45 men can complete a piece of work in 16 days. Four days they started working , 36 more men joined them. How many days will they take to complete the remaining work ?

Solution(By Examveda Team)

According to the question,
Let the remaining work is complete in D days
$${\text{4}}{{\text{5}}_{{\text{men}}}} \times {\text{1}}{{\text{6}}_{{\text{days}}}}$$    = $$\left( {{\text{4}}{{\text{5}}_{{\text{men}}}} \times {{\text{4}}_{{\text{days}}}}} \right)$$    + $${\left( {{\text{45}} + {\text{36}}} \right)_{{\text{men}}}}$$   $$ \times {\text{D}}$$
$$\eqalign{ & \Rightarrow \frac{{540}}{{81}} = {\text{D}} \cr & \Rightarrow {\text{D}} = 6\frac{2}{3}{\text{ days}} \cr} $$