Time and Work Questions

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?

Jaikishen can do a piece of work in 15 hours. If he is joined by Jhanvi who is 50% more efficient, in what time will they together finish the work?

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?

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?

Mother can bake 20 cakes in 4 hours, Mother and Dadima together can bake 60 cakes in 10 hours. How many cakes Dadima can bake in 30 hours?

A can do a piece of work in 8 days and B can do it in 10 days seperately. How many days would it take for both A and B to finish the same work together?