Time and Work Questions

In a camp 180 students had ration for 20 days. How many students should leave the camp if the ration should last for 25 days?

An hour-long test has 60 problems. If a student completes 30 problems in 25 minutes, then the required seconds he has taken on average for computing each of the remaining problems is

B is thrice as efficient as A and C is 0.75 times as efficient as A. What is the ratio of number of days taken by A, B and C when they work individually?

Five men or ten women can complete a job in 20 days. In how many days can 3 men and 4 women complete it?

A, B and C can finish a job working alone in 20, 30 and 60 days respectively. They all work together for 1 day, then A and B quit. How many days C working alone will take to finish the remaining part of the job?

A mason can build a wall in 18 hours. After 9 hours he takes a break. What fraction of the wall is yet to be built?

A and B together can do a piece of work in 36 days, B and C together can do it in 24 days. A and C together can do it in 18 days. The three working together can finish the work in

A, B and C can do a job working alone in 6, 9 and 18 days respectively. They all work together for 1 day, then A and B quit. How many days C working alone will take to complete the remainder of the job?