Time And Work

71 A does 4/5 of a work in 20 days. He then calls in B and they together finish the remaining work in 3 days. How long B alone would take to do the whole work?

72 A can do a certain work in the same time in which B and C together can do it. If A and B together could do it in 10 days and C alone in 50 days, then B alone could do it in:

73 X can do a work in 16 days. In how many days will the work be completed by Y, if the efficiency of Y is 60% more than that of-X?

74 When A alone does a piece of work, he takes 16 days more than the time taken by (A + B) to complete the work, while B alone takes 9 days more than the time taken by (A + B) to finish the work. What time, A and B together will take to finish this work?

75 A alone can do a piece of work in 6 days and B alone in 8 days. A and B under took to do it for ₹ 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C?

76 A and B together can do a piece of work in 30 days. A having worked for 16 days, B finishes the remaining work alone in 44 days. In how many days shall B finish the whole work alone?

77 X can do 1/4 of a work in 10 days, Y can do 40% of the same work in 40 days and Z can do 1/ 3 of the work in 13 days. Who will complete the work first?

78 A and B can complete a work in 12 days and 18 days, respectively. A begins to do the work and they work alternately one at a time for 1 day each. The whole work will be completed in how many days?

79 A contract is to be completed in 92 days and 234 men were set to work, each working 16 h a day. After 66 days, 4/7 of the work is completed. How many additional men may be employed, so that the work may be completed in time, each man now working 18 h a day?

80 If one man or two women or three boys can finish a work in 88 days, then how many days will one man, one woman and one boy together take to finish the same work?