Time and Work - Class 7 Mathematics CBSE ICSE

Improve your understanding of Time and Work by practicing the below questions from class 7 Mathematics.
A hostel has food commodities for 100 students for 40 days. After 4 days, 20 more students join the hostel. How long will the remaining food commodities last?
A and B together can build a wall in 30 days. If A is twice as good as a workman as B, in how many days A alone can finish the work?
A can do a piece of work in 40 days. He works at it for 8 days and then B finishes the remaining work in 16 days. How long will they take to complete the work if they do it together?
Ramesh and Shravan can do a piece of work in 45 days and 40 days respectively. They began the work together. But Ramesh leaves after some days and Shravan finished the remaining work in 23 days. After how many days did Ramesh leave?
13 men can weave 117 baskets in a week. How many more men will be needed to weave 189 baskets in 3 days?
A and B separately do a work in 10 days and 15 days respectively.They worked together for some days and then A completed the remaining work in 5 days. For how many days they have worked together?
A can do a piece work in 10 days, B can do it in 12 days and C in 15 days. All three of them begin to work together. But A leaves the work after 2 days and B leaves three days before the completion of the work. How long did the work last?
Rohit can do a piece of work in 20 days, while Shyam can do it in 30 days. If both of them work at if together, in how many days will they be able to find the work?
24 computers operetors working 6 hours a day can finish a project in 14 days.If each operator works 7 hours in a day, find the number of operators.
7 workers working 6 hours a day can build a wall in 12 days. How many more days will 3 workers take to build a similar wall, working 8 hours a day?