Time & Work practice Questions level 2
1) Machine A can do a work in 20 days. An advanced machine B is 25% more efficient than A. In how many days can they complete the work, if they work together?
(A) 6 7/9 days
(C) 8 1/9 days
(B) 8 8/9 days
(D) 9 1/9 days
2) A certain work can be done by A and B, B and C and A and C in 4 4/5. 6 6/7 and 5 1/3days respectively. Find the number of days in which A, B, C can do the work alone respectively.
(A) 8, 12, 16
(B) 9, 12, 18
(C) 9, 15, 18
(D) 12, 16, 18
3) A can complete a piece of work in 12 days. A starts the work, works for 4 days and quits. B and C take over and complete the remaining work in 12 days. If B can complete half of the work in 12 days, find the time taken by C alone to complete the work.
(A) 54 days
(B) 60 days
(C) 72 days
(D) 80 days
4) Naresh works for 3 days and quits from a project, which he can complete in a total of 12 days. Now, Suresh takes over the project and completes it in 12 days. In how many days the project would have been completed, if they had worked together?
(A) 6 1/7 days
(B) 6 3/7 days
(C) 8 3/7 days
(D) 6 6/7 days
5) A can complete a certain work in 8 days. A and B work for 2 days and then A leaves and C joins B and both work together and complete the remaining work in 4 days. In how many days can B alone complete the work, if C alone can complete the work in 16 days?
A)12 days
B)16 days
C)20 days
D)24 days
6) P can complete a certain work in 18 days, Q and F can complete the same work in 9 days and 6 days respectively. P starts the work and after working for 3 days, he is joined by Q and they work together for another 3 days. Then they are joined by R an together they complete the work. What percentage of the work is done by P?
A)25%
B)66%
C)88%
D) 38.88%
7) In a company, the engineers plan to do a certain work in 8 days with 8 machines. But, after 3 days. they find that only 30% of the work is done with the machines running for 5 hours day. If they want to complete the work in the planned time with the machines, how many hours per day the machines have to work?
(A) 4 hours
(B) 5 hours
(C) 6 hours
(D) 7 hours
8) A frog, which is at the bottom of a 50 m deep well, is trying to come out of it. In every jump it covers 1-25 m but slips 0.75 m. In how many jumps it would come out of the well?
(A) 98
(B) 99
(C) 100
(D) 101
9) L, M and N are three machines, which produce electronic gadgets, the efficiencies of production of which are in the ratio 2: 4:5. If L works for 7 days, M for 4 days and N for 2 days, they produce 1680 gadgets. How many gadgets are produced if L, M and N work for 3, 6, 4 days respectively?
(A) 1720
(B) 1860
(C) 2100
(D) 2240
10) If P, Q and R earned $ 295 working together on a job, which each can do in 5, 6 and 8 days respectively, what is the share of R?
(A) 150
(B) 120
(C) 100
(D) 75
11) P, Q and R work for a certain company and can reach a certain target in 4 hours, 6 hours, and 12 hours respectively. On a certain day all three of them start working for the target together. P stops after 1 hour, Q works for 1 more hour and then stops. R works until the target is reached. Find the percentage of the work done by R in reaching the target.
(A) 16.67%
(B) 25%
(C) 41.67%
(D) 50%
12) There are four persons who can do a work in 19 days each, individually. The work is started by one of the persons on the first day. Everyday one more person joins and starting from the fourth day, all the four people work together. In how many days will the work be completed?
(A) 6 ¼ days
(B) 6 1/19 days
(C) 7 days
(D) 7 1/19 days
13) A house can be painted by 7 men and 2 women in 8 days, if they work for 12 hours a day. Working at the same rate, 6 men and 20 women can do the same job in 4 days in how many hours can 8 men and 8 woman paint the house?
(A) 12 hours
(B) 16 hours
(C) 32 hours
(D) 64 hours
14) P,Q and R can do a piece of work in 4, 6 and 12 days respectively, working for 12 hours a day. On Each day, P starts the work and works for 8 hours, then Q works for 8 hours and then R works for 8 hours. In the same way they continue until P leaves after 2 days of work. Then Q and R work alternately for 8 hours each till the work is completed. In how many days in the work completed?
(A) 3 1/3 days
(B) 3 ½ days
(C) 3 2/3 days
(D) 3 ¾ days
15) P and Q can do a certain work together in 12 days, Q and R in 20 days, and P and R in 15 days. P, Q and R start working together. They work for 2 days after which Q leaves. After 10 more days Q rejoins and P leaves. Q works for 2 days along with R and then he leaves. The remaining work is completed by R. In how many days will the work be completed?
(A) 12 days
(B) 16 days
(C) 20 days
(D) 24 days
16) Tap B takes thrice the time taken by tap A to fill a tank. It takes 12 hours to fill the tank if the two taps are working and are opened simultaneously. How much time does it take to fill the tank, if tap B alone is open?
(A) 60 hours
(B) 36 hours
(C) 48 hours
(D) 64 hours
17) In a tank there are two taps which can fill the tank in 6 hours and 12 hours. At the time when the tank should have been full, it was observed that the tank is only 3/4 full due to a crack at the bottom. In how much time the crack could have emptied a full tank?
(A) 10 hours
(B) 12 hours
(C) 16 hours
(D) 20 hours
18) A, B and C can do a piece of work in 6, 8 and 10 hours respectively. Find the time taken by A, B and C working together, to do a work which can be done by C alone in 25 hours.
(A) 6 29/47 hours
(B) 6 20/47 hours
(C) 6 19/47 hours
(D) 6 18/47 hours
19) A and B are two taps which can fill a tank in 6 and 9 hours respectively, C is an emptying tap, which can empty the tank in 7.5 hours. Tap B is opened 3 hours after tap A is opened. For how much time tap C has to be opened if the tank has to be filled in 6 hours?
(A) 1½ hours
(B) 2 ½ hours
(C) 3 hours
(D) 5 hours
20) P,Q,R and S are four taps which can fill a tank in 36,18, 12 and 6 hours respectively, if P is opened at 10:00 am, Q at 10:30 am., R at 11:00 am and Sat 11:30a.m. At what time is the tank filled?
(A) 1:35 p.m.
(B) 2:05 pm
(C) 2:25 pm.
(D) 2:45 p.m.
21) Three machines P, Q and R can do a piece of work in 7,9 and 10 days respectively. Due to a problem in P and Q, they are working only at 70% and 90% of their efficiencies respectively. In how many days p,
Q and R together can do the work?
(A) 1 2/3 days
(B) 2 1/3 days
(C) 2 2/3 days
(D) 3 1/3 days
22) Three men A, B and C working together can do a work in 30 days they start work together A works for 3 days and takes rest on the fourth day, B works for 5 days and takes rest on next two days and C works for 7 days and taken rest on next thro days. In how many days will the work be completed? (Given that A, B and C work at the same rate.)
(A) 39 days
(B) 40 days
(C) 41 days
(D) 42 days
23) A can do a piece of work in 20 days working and B can do the same work in 30 days. They finished the work with the help of C in 8 days. If they earned a total of Rs 5550, then what is the share of C?
(A) 1800
(B) 1850
(C) 1900
(D) 1950
24) X, Y and Z can individually complete a piece of work in 27, 36 and 54 days respectively. They worked one day each, with X starting the work, followed by Y the next day and Z the next day. They continued working like that till the 24th day, after which the remaining work was completed by X and Z working on alternate days with X working on the 25th day. In how many days was the work completed?
(A) 28
(B) 30
(C) 32
(D) 36
25) Two taps P and Q which can independently fill at tank in 15 hours and 30 hours respectively were opened simultaneously, when the tank was empty. When the tank was half full, an emptying tap R was opened. If the emptying tap R can empty the full tank in 20 hours, than totally in how much time will the tank be completely filled?
(A) 12 hours
(B) 15 hours
(C) 18 hours
(D)20 hours
key sheet :
1.c 2.a 3.c 4.d 5.a 6.d 7.d 8.b 9.c 10.d 11.c 12.a 13. d 14. a 15. b 16.c 17.c 18.d 19. b 20.b 21.d 22.c 23.b 24.d 25.b