A, B and C alone can complete the whole work in 10 days, 15 days and 20 days respectively. If A and B started the work together for 2 days and left the work, then C and D together can complete the remaining work in 5 days. Find the time taken by D alone to complete the whole work.
1
10 days
2
15 days
3
14 days
4
12 days
5
16 days