Time And Work(Quantitative Aptitude ) Questions and answers for exam Preparation

Quantitative Aptitude

TIME AND WORK MCQs

Time & Work, Work And Wages

Total Questions : 1512 | Page 147 of 152 pages

Question 1461. Two pipes P and Q can fill a cistern in 12 min. and 15 min. respectively but a third pipe ‘R’ can empty the full tank in 6 min. P and Q are kept open for 5 min. in the beginning and then ‘R’ is also opened. In what time is the cistern emptied ?

30 min
35 min
40 min
45 min

Discuss Question

Answer: Option D. -> 45 min
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 1462. A and B can together do a piece of work in 15 days. B alone can do it in 20 days. In how many days can A alone do it ?

40 days
50 days
60 days
70 days

Discuss Question

Answer: Option C. -> 60 days
(A+B)’S 1 DAY’S WORK = [1/15−1/20]=1/60
A ALONE CAN FINISH IT IN 60 DAYS

Question 1463. A completes 80% of a work in 20 days. Then B also joins and A and B together finish the remaining work in 3 days. How long does it need for B if he alone completes the work?

37 ½ days
22 days
31 days
22 days

Discuss Question

Answer: Option A. -> 37 ½ days
WORK DONE BY A IN 20 DAYS = 80/100 = 8/10 = 4/5
WORK DONE BY A IN 1 DAY = (4/5) / 20 = 4/100 = 1/25 — (1)
WORK DONE BY A AND B IN 3 DAYS = 20/100 = 1/5 (BECAUSE REMAINING 20% IS DONE IN 3 DAYS BY A AND B)
WORK DONE BY A AND B IN 1 DAY = 1/15 —(2)
WORK DONE BY B IN 1 DAY = 1/15 – 1/25 = 2/75
=> B CAN COMPLETE THE WORK IN 75/2 DAYS = 37 ½ DAYS

Question 1464. 12 buckets of water fill a tank when the capacity of each bucket is 13.5 litres. How many buckets will be needed to fill the same tank, if the capacity of each bucket is 9 litres?

Discuss Question

Answer: Option D. -> 18
CAPACITY OF THE TANK = (12×13.5)=162 LITRES
CAPACITY OF EACH BUCKET = 9 LITRES.
NUMBER OF BUCKETS NEEDED = 162/9=18

Question 1465. A leak in the lower portion of a tank can empty the full tank in 9 hrs. An inlet pipe fills water at the rtae of 10 lit. a minute. When the tank is full, the inlet is opened and due to leak, the tank is empty in 16 hrs. How many litres does the cistern hold ?

12,342 litres.
12,444 litres
12,566 litres.
None of these

Discuss Question

Answer: Option A. -> 12,342 litres.
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 1466. A alone can finish a work in X days. B alone can finish the same work in X+5 days. Together, they take 6 days to complete the work. Find X

Discuss Question

Answer: Option C. -> 10
PART OF WORK COMPLETED BY A IN A DAY = 1/X PART OF WORK COMPLETED BY B IN A DAY
= 1/(X+5) (1/X)+(1/(X+5)) = 1/6 (2X+5)/(X²+5X) = 1/6 X²+5X = 6(2X+5) X²-7X-30=0 SOLVING, X=10

Question 1467. A can do (1/3) of a work in 5 days and B can do (2/5) of the work in 10 days. In how many days both A and B together can do the work ?

75/8 days
44/6 days
48/5 days
None of these

Discuss Question

Answer: Option A. -> 75/8 days
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 1468. P and Q need 8 days to complete a work. Q and R need 12 days to complete the same work. But P, Q and R together can finish it in 6 days. How many days will be needed if P and R together do it?

Discuss Question

Answer: Option B. -> 8
LET WORK DONE BY P IN 1 DAY = P
WORK DONE BY Q IN 1 DAY =Q
WORK DONE BY R IN 1 DAY = R
P + Q = 1/8 —(1)
Q + R= 1/12 —(2)
P+ Q+ R = 1/6 —(3)
(3) – (2) => P = 1/6 – 1/12 = 1/12
(3) – (1) => R = 1/6 – 1/8 = 1/24
P + R = 1/12 + 1/24 = 3/24 = 1/8
=> P AND R WILL FINISH THE WORK IN 8 DAYS

Question 1469. A tap can fill a tank in 32 min. and another can empty it in 16 min. If the tank is already half full and both the tanks are opened together, the tank will be_________?

12 min
14 min
16 min
20 min

Discuss Question

Answer: Option C. -> 16 min
IN THIS PROBLEM, RATE OF WATER PIPE (WASTE) IS MORE, THE TANK WILL BE EMPTIED WHEN THE PIPES ARE OPENED.
WORK DONE IN TOTAL EMPTYING IN 1 MIN.
=1/16−1/32=1/32
NOW, FULL TANK WILL BE EMPTIED BY THEM IN 32 MINUTES.
HALF FULL TANK WILL BE EMPTIED IN 16 MINUTES.

Question 1470. P can do a work in the same time in which Q and R together can do it. If P and Q work together, the work can be completed in 10 days. R alone needs 50 days to complete the same work. then Q alone can do it in__________?

30 days
25 days
20 days
15 days

Discuss Question

Answer: Option B. -> 25 days
WORK DONE BY P AND Q IN 1 DAY = 1/10
WORK DONE BY R IN 1 DAY = 1/50
WORK DONE BY P, Q AND R IN 1 DAY = 1/10 + 1/50 = 6/50
BUT WORK DONE BY P IN 1 DAY = WORK DONE BY Q AND R IN 1 DAY . HENCE THE ABOVE EQUATION CAN BE WRITTEN AS
WORK DONE BY P IN 1 DAY × 2 = 6/50
=> WORK DONE BY P IN 1 DAY = 3/50
=> WORK DONE BY Q AND R IN 1 DAY = 3/50
HENCE WORK DONE BY Q IN 1 DAY = 3/50 – 1/50 = 2/50 = 1/25
SO Q ALONE CAN DO THE WORK IN 25 DAYS