Time and Work Questions

A mason can build a wall in 70 hours. After 7 hours he takes a break. What fraction of the wall is yet to be built?

X, Y and Z can do a piece of work in 30, 40 and 50 days respectively. All three of them began the work together but Y left 4 days before completion of the work. In how many days was the work completed?

Manish is four times as efficient as Puneet. Manish takes 90 days less than Puneet to complete a book. If both of them work together, then in how many days the book will be completed?

A can do a piece of work in 18 days. He worked at it for 12 days and B finished the remaining work in 8 days. B alone can do the whole work in

A does 1/2 as much work as B and C does1/2as much work as A and B together. If C alone can finish the work in 40 days, then together all will finish the work in

S does half as much work as T in 1/7 of the time taken by T. If together they take 21 days to complete a work, then how may days shall S take to complete that work alone?

A can do a work in 15 days and B in 20 days. If they work on it together for 5 days, then what fraction of work is left?

Type 1 workers can do three times the work of Type 2 workers. Twelve Type 1 workers can complete a task in 10 days. How many days would it have taken 4 Type 1 and 8 Type 2 workers to complete the same task?