A and B together can do a job in 6 days. A alone does it in 9 days. In how many days can B alone do it?
Show answer & explanation
Correct answer: A
Explanation
Given:
A and B work together = 6 days
A alone work = 9 days
By the formula:
1/A + 1/B = 1/(A + B)
1/9 + 1/B = 1/6
1/B = 1/6 − 1/9
1/B = (3 − 2) / 18
1/B = 1/18
B = 18
B alone will complete the work in 18 days.