A and B can do a certain work in 25 and 20 days, respectively. They work together for 4 days. The remaining work is completed by C in 8 days. C alone can complete 40% of the original work in :
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 5 days.
LCM(25, 20) = 100
The efficiency of A = 100/25 = 4 units
The efficiency of B = 100/20 = 5 units
Work done in 4 days = (4 + 5) × 4 = 36 units
Remaining work = 64 units
Efficiency of C = 64/8 = 8 units
Time taken by C to complete 40% of the original work = = = 5 days