A and B together finish a job in 9 days. If A alone takes 18 days, how many days will B alone take?
Show answer & explanation
Correct answer: C
Explanation
Given:
A + B's time = 9 days
A's time = 18 days
By formula:
Work rate = 1 / time
A + B's rate = 1/9
A's rate = 1/18
B's rate = 1/9 − 1/18
= (2 − 1) / 18
= 1/18
B's time = 18 days