Correct option is C
Given:
- A completes the work in 4 days
- B completes the work in 20 days
Solution:
Total work = LCM of 4 , 20 = 20 unit
Efficiency of A = 20/4 = 5
Efficiency of B = 20/20 = 1
With the help of C they can complete 2 days
Efficiency of A + B + C = = 10 unit
Efficiency of C = 10 - 5 -1 = 4 unit/day
C alone complete tte work = days