Question: a can do a piece of work in 15 days?
Answer: Then for completing the balance work, A will need = 15/100 * 50 = 7.5 days. If they have worked together and B leaves after 5 days, then 5/6 th of the work would have been over. Hence, for finishing the balance work, A will take = 15 * 1/6 = 2.5 days.