New Learning Composite Mathematics SK Gupta Anubhuti Gangal Class 8 Variation Self Practice 9C Solution
(1) 6 men take 12 hours to weed a certain field. How long would 9 men take to do so, if all work at the same rate?
(2) 12 men can hoe a field in 10 days. How long will 15 men take?
(3) A and B can do a piece of work in 6 and 12 days respectively. They (both) will complete the work in how many days?
(4) Rekha can finish a work in 18 days and Prema can do the same work in half the time taken by A. Then, working together, what part of the same work they can finish in a day?
(5) A alone can complete a work in 12 days and B alone can complete the same work in 24 days. In how many days can A and B together complete the same work?
(6) A and B together can do a piece of work in 12 days, while B alone can finish it in 30 days. In how many days can A alone finish the work?
(7) A, B and C can complete a work in 2 h. If A does the job alone in 6 h and B in 5 h, how long will it take C to finish the job alone?
(8) A and B can do a piece of work in 72 days. B and C can do it in 120 days. A and C can do it in 90 days. In what time can A alone do it?
(9) A can do a piece of work in 10 days and B in 20 days. They begin together but A leaves 2 days before the completion of the work. In how many days will the whole work be completed?
(10) Piyush and Ajit together can complete a work in 3 days. They started together but after 2 days Ajit left the work. If the work is completed after 2 more days, Piyush alone can complete it in how many days?
(11) A can complete a work in 10 days, B in 12 days and C in 15 days. all of them began the work together, but A had to leave the work after 2 days of the start and B, 3 days before the completion of the work. How long did the work last?
(12) Sanjay and Ranbir can do a piece of work in 45 and 40 days respectively. They began the work together but Sanjay leaves after some days and Ranbir finished the remaining work in 23 days. After how many days did Sanjay leave?