M alone can complete a work in 50 days and N alone can complete the same work in 100 days . If both of them work together, then in 25 days, what percent of the total work will be completed?
Answer & explanation
Correct answer: option 3
Total work = 100
Efficiency of M and N = 3
Work will be completed by M and N together in = $\frac{Total\;work}{efficiency}$
= $\frac{100}{3}$
Amount of work done in 25 days = 25 x work done in 1 day
= 25 x $\frac{3}{100}$ = 75
Percentage of work completed = $\frac{75}{100}$ x 100 = 75%