A company employed 200 workers to complete a certain work in 150 days. If only $$\frac{1}{4}$$ th of the work had been done in 50 days, then in order to complete the whole work in time, the number of additional workers to be employed were ?

$$\eqalign{ & \Rightarrow \frac{{{{\text{M}}_1}{{\text{D}}_1}}}{{{{\text{W}}_1}}} = \frac{{{{\text{M}}_2}{{\text{D}}_2}}}{{{{\text{W}}_2}}} \cr & \Rightarrow \frac{{200 \times 50}}{{\frac{1}{4}}} = \frac{{{{\text{M}}_2} \times 100}}{{\frac{3}{4}}} \cr & \Rightarrow {{\text{M}}_2} = 300 \cr & {\text{So, additional men}} \cr & = 300 - 200 \cr & = 100 \cr} $$