A contractor undertakes to built a walls in 50 days. He employs 20 peoples for the same. However after 25 days he finds that only 40% of the work is complete. How many more man need to be employed to complete the work in time?  Select:
A) 25	B) 30	C) 35	D) 30	E) None of these
20 men complete 0.4 work in 25 days.   Applying the work rule, m1 × d1 × w2 = m2 × d2 × w1   we have,   20 × 25 × 0.6 = m2 × 25 × 0.4   or m2 = 20×25×0.6/25×0.4 = 30 men   Answer30
<result>D</result>
A contractor undertakes to built a walls in 50 days. He employs 20 peoples for the same. However after 25 days he finds that only 40% of the work is complete. How many more man need to be employed to complete the work in time?