Time and Work Questions

P alone can do a piece of work in 8 days and Q alone can do the same work in 10 days. In how many days will both together complete the same work?

A can do a work in 20 days and B in 50 days. If they work on it together for 5 days, then what fraction of work is left?

A, B and C can finish a job working alone in 12, 8 and 24 days respectively. In how many days they can finish the job if they worked together?

A can do a work in 36 days and B in 12 days. If they work on it together for 3 days, then what fraction of work is left?

A can do a work in 15 days and B in 20 days. If they work on it together for 5 days, then what fraction of work is left?

X, Y and Z can do a piece of work in 30,40 and 50 days respectively. All three of them began the work together but Y left 4 days before completion of the work. In how many days was the work completed?

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?

Akka can bake 100 cakes in 20 hours, Akka and Tai together can bake 75 cakes in 10 hours. How many cakes Tai can bake in 20 hours?