To do a certain work, the ratio of the efficiencies of A and B is 7 : 5. Working together, they can complete the same work in 17days. A alone will complete 60% of the same work in :
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 18 days
Let the efficiency of A and B is 7x and 5x.
Total work = Number of days × total efficiency
Total work = 35/2 × 12x
= 210x
60% of work = 210 × 60% = 126x.
Time taken by A to finish 126x units of work = 126x/7x = 18 days.