P and Q can complete a work in 9 days and 15 days, respectively. If they work together for three days, then in how many days will the remaining work be completed by Q alone?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 7.
Given that
9 * P = 15 * Q
P: Q = 15: 9
Let the remaining work be completed by Q alone = d days
According to the question
(P + Q) * 3 + Q * d = total work = 9 * 15 = 135
( 15 + 9) * 3 + 9 * d = 135
9 * d = 135 - 72 = 63
d = 7 days