A can do a piece of work in 15 days and B alone can do it in 10 days. B works at it for 5 days and then leaves. A alone can finish the remaining work in Choose the correct option:
A) 5days
B) 6days
C) 7.5days
D) 8.5days
E) 9days
Explanation:   B's 5 days work =   1/10∗5=1/2   Remaining work =1−1/2=1/2   A can finish work =15∗1/2=7.5days   Option 7.5days
<result>C</result>
A can do a piece of work in 15 days and B alone can do it in 10 days. B works at it for 5 days and then leaves. A alone can finish the remaining work in