Correct option is C
Given:
A complete the work in 9 days
B complete the work in 15 days
Solution:
A’s one day work = unit
B’s one day work = unit
A+B’s one day work =
A+B complete the total work in
Alternate Solution:
Efficiency of A = 3 unit
Efficiency of B = 5 unit
Time required to complete whole work by A+B together =