Time and Work Questions

A and B can together complete a task in 18 hours. After 6 hours A leaves. B takes 36 hours to finish rest of the task. How many hours would A have taken to do the task if he worked alone?

Pramod can paint a wall red in 12 hours while Brajen can whitewash the wall completely in 16 hrs. If Pramod and Brajen work alternately for an hour each starting when the wall has just cement on it till when it is completely painted red, how many hours will it take to paint the entire wall red?

Ajay can do a painting in 12 days. Amit is 70% more efficient than Ajay. What is the number of days Amit would need to finish the same painting?

A, B and C can complete the work in 4, 5 and 6 hours respectively. If they all work together and receive Rs. 777 as wages then find the share of A.

A painter can paint a fence in 24 hours. After 6 hours he takes a break. What fraction of the fence is yet to be painted?

P and Q can do a project in 12 and 12 days respectively. In how many days can they complete 50% of the project if they work together?

Sashi can do a piece of work in 20 days. Tanya is 25% more efficient than Sashi. The number of days taken by Tanya to do the same piece of work is:

Vikram and Vivek can finish a work in 50 days. They worked together for 20 days and then left. How much work has been done by them?