Question

5 Two teachers A and B can complete an academic work in 10 days and 15 days respectively. They started the work
together, but A left after 5 days and another teacher C joined, who alone can complete the work in 60 days. In how
many days the work got completed?

Answer

1. 7
2.145:93
3.137:101
4.149:89​

Answer 1

Answer:

according to my knowledge the days are not in ratio so the answer will be 7

Answer 2

I didn't understand the question