A can do a piece of work in 21 days and B in 28 days. Together they started the work and B left after 4 days. In how many days can A alone do the remaining work ?
Correct Answer: 14 days
Explanation:
Let A worked for x days.
x/21 + 4/28 = 1 => x = 18
A worked for 18 days. So, A can complete the remaining work in 18 - 4 = 14 days.
