A completes a work in 2 days, B in 4 days, C in 9 and D in 18 days. They form group of two such that difference is maximum between them to complete the work. What is difference in the number of days they complete that work?
14/3
8/3
5/3
None of these
Explanation:
If C and D form a pair and A and B form a pair the difference is maximum.
Now C and D together can complete the work = 9×189+189×189+18 = 6 days.
A and B together can complete the work = 2×42 + 42×42 + 4 = 4/3 days.
Difference = 6 - 4/3 = 14/3 days.