Time and Work Questions

A piece of work was finished by A, B and C together. A and B together finished 60% of the work and B and C together finished 70% of the work. Who among the three is most efficient?

A can do a work in 21 days and B in 42 days. If they work on it together for 7 days, then what fraction of work is left?

Amar is 2 times as good a workman as Badal and therefore is able to finish a job in 15 days less than Badal. In how many days can they together complete the job?

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 does 50% of a work in 12 days. He then calls in B and they together finish the remaining work in 8 days. How long B alone would take to complete the whole work?

A can do as much work in 4 days as B can do in 5, and B can do as much work in 6 days as C in 7. In what time will C do a piece of work which A can do in a week ?

Sumit is 28% less efficient than Amit. If Amit can make a wall in 54 days, then Sumit can complete the same work in how many days?

Badki can bake 45 cakes in 9 hours, Badki and Chutki together can bake 80 cakes in 10 hours. How many cakes Chutki can bake in 40 hours?