GATE Mechanical

Q1.A can do a piece of work in 9 days; B can do the same work in 12 days.in how many days can the work be completed if A and B work together?

Q2.Three men A,B,C complete the work 10,12,15 days.A,B,C starts work together ,A and B left the work 2 days before the completion of the work ,then the whole work will finish in how many days?

Q3.P,Q and R takes 7,12,14 days respectively to complete a job, working  individually.with the help of S,P,Q,R together complete the work in 2 days.find the S’s share in total of 4200 paid them.

Q4.P and Q working together can complete a piece of work in 24 days.the ratio of their efficiency is 2:3.in how days can the faster person complete the work working alone?

Q5.A+B,B+C,C+A can do a work in 20,30 and 40 days respectively.in how many days A alone complete the same work?

Q6. A+B can complete a work 40% leasser time than C,while B+C can complete the same work in 60% lesser time than A,if they together can complete the whole work in 20 days.then in how many days  A will alone complete the same work?

Q7. P and Q can do a certain work in 28 days and 56 days.P works for 7 days and then Q joins P. In how many more days can they complete the remaining work?

Q8. A and B can complete a work in 12 and 15 days, they started the work alternatively for 1 day each and a started the work first .in how much time 80% of the work will be completed?

Q9. If P ,Q and R earn 295 working together on a job,which P,Q and R can complete in 5,6 and 8 days respectively .what is the share of R?

Q10. 60 men can complete a work in 40 days.they started the work together but after every 10 days 5 men leave the work.in how many days the work will be completed?

Q11.2 men can complete a work in 3 days, while 3 women can complete the same workin 4 days &4 children can complete the same work in 6 days.in how many days 1men+2children can complete the same work.

Q12.there is sufficient food for 400 soldiers for 31 days. After 28 days,280 solders left the camp .for how many days will the rest of the food last for the rest of the soldiers.

Q13.5 men can prepare 10 toys in 6 days working 6 hrs per day.in how many days can 12 men 16 toys working 8 hrs per day.

Q14.Two fill pipes A &B can fill a cistern in 18 and 24 mint respectively. Both fill pipes are open together,but 6 mints before the cistern will fill pipe A is closed.in how much time will the cistern take to fill?

Q15.Two taps A &B can fill tank in 10hrs and 12hrs respectively. there is outlet tap C.if all the taps open together the tank will fill in 30 hrs.in how many hours tap C alone can empty the tank?

Q16.A and B can fill tank in 15 and 20 hrs respectively. Both the taps open together ,when the tank was ¼ th full,a leak is develop in the bottom of tank, through which 1/5 th of the water supply by both the pipes leaks out .find in how many hours tank will fill?

Q17.A cistern can be filled by two filling pipes separately in 12 and 16 min respectively. Both pipes are open together ,for a certain time out being clogged only 7/8 of quantity of water flows through former and 5/6 through the latter pipe .the obstruction is removed ,the cistern is filled in 3 min from that moment .how long was it before the full flow began?

Q18.Tap P, which can fill a tank in 60 mints, is opened at 6: 00pm.Tap Q which can fill the tank in 30 mint is opened at 6:10 pm. And tap R, which can fill the tank in 20 mint is opened at 6:20pm.at what time will the tank be filled?

Q19.A and B are two taps which can fill a tank in 6hrs and 12 hrs .At the time when the tank should have been full, it was observed that the tank is only ^Th full due to crack at the bottom ,in how much time could the crack have emptied a full tank(hours)?

Q20.P works 25% more efficient than Q and Q works 50% more efficient than R. To complete a certain project alone takes 50 days less than Q alone. If, in this project P alone works for 60 days and then Q alone works for 125 days,in how many days can R alone complete  the remaining work?

(C)100      (D)150