Time and Work Questions

10 persons can do a job in X days. If 20 persons with twice the efficiency can do the same job in 5 days, then find the value of X?

X alone can do a piece of work in 12 days and Y alone can do the same work in 6 days. In how many days will both together complete the same work?

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?

Anil can do a piece of work in 14 days which Rohit can do in 21 days. They worked together for few days after which Anil left. If Rohit worked alone for 3 days, find the total number of days it took to complete the whole work.

If Mr. Raghav taught a total of 500 hours, then what is the difference in number of hours of teaching algebra and modern Maths?

X does 25% of a work in 20 days. Y joins X and they together finish the remaining work in 15 days. Y alone can do the whole work in ___ days.

A man starts moving from a place A and reaches the place B in 26 hours. He covers 1/3rd of the distance at the speed of 4 km/hr and covers the remaining distance at the speed of 5 km/hr. What is the distance (in km) between A and B?

Both A and B together can complete a work in 20 days and B alone can complete the same work in 36 days. In how many days will A alone complete the work?