Bunuel
4 men and 10 women were assigned to complete a work. Can they complete the work within 15 days? Assume that all men are equally efficient and all women are equally efficient.
(1) 4 men and 10 women employed initially completed 1/3 of the work in less than 6 days.
(2) If 2 additional men and 2 additional women had been employed, they would have completed 1/2 of the work in 5 days (the additional men and the additional women
have efficiencies equal to the men and women employed initially, respectively).
4M & 10 W can complete the task within 15 days?
(1) says if 4 M & 10 W initially complete the 1/3 task in less than 6 days
if they completed in 3 days then they will finish total task in 9 days (within 15 days) but
if they completed the task in 5.5 days then they will finish the task in 16.5 days (beyond 15 days)
Hence Not sufficient
(2) if 4M+2M and 10W+2W are working they can finish 1/2 task in 5 days and hence the complete task in 10 days
so these 6M + 12W = 10 days
1M + 2W = 60 days
4 M + 8W = 15 days in question wee have 4M + 10W (they will finish the task before 15 days)
and hence Sufficient
B