A can do a piece of work in 30 days, while B alone can do it in 40 days. In how many days can A and B working together do it?
A17 and 1/7
B27 and 1/7
C42 and 3/4
D70
Answer:
A. 17 and 1/7
Read Explanation:
The LCM of (30 , 40) = 120
Total work = 1120 unit
Efficiency of A = 120/30 = 4
Efficiency of B = 120/40 = 3
Efficiency of A + B = 4 + 3 = 7
Time taken by A and B to complete the work = 120/7 = 17 1/7 days