Directions: Each of the questions given below is followed by series of options among which you have to choose the best one. You can also review your choices by clicking into answer section.
16. C takes 6 days to complete half of a work and D takes 5 days to complete 1/3rd of the same work. They take turns to complete the task. If C works for the first 4 days, in how many days will D complete the rest of the work without the help of C?
A. 10 days
B. 12 days
C. 8 days
D. 9 days
Answer
Explanation:
Part of work completed by C in 1 day = 1/12
Part of work completed by D in 1 day = 1/15
Part of work completed by C in 4 days = 1/3
Work remaining = 2/3
Time taken by D to complete the work = (2/3)÷(1/15) = 10 days.
17. 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?
A. 30 days
B. 40 days
C. 60 days
D. 70 days
Answer
Explanation:
Let A's 1 day's work = x and B's 1 day's work = y.
Then, x + y = (1/30) and 16x + 44y = 1.
Solving these two equations, we get: x = (1/60) and y = (1/60)
B's 1 day's work = (1/60) .
Hence, B alone shall finish the whole work in 60 days.
18. A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in:
A. 4 days
B. 6 days
C. 8 days
D. 12 days
Answer
Explanation:
Suppose A, B and C take x, (x/2) and (x/3) days respectively to finish the work.
Then, (1/x) + (2/x) + (3/x) = (1/2)
(6/x) = (½)
x = 12.
So, B takes (12/2) = 6 days to finish the work.
19. If 10 men or 18 boys can do a piece of work in 15 days, then 25 men and 15 boys together will do twice the in…………
A. 4 and half days
B. 8 days
C. 9 days
D. 36 days
Answer
Explanation:
10 men = 18boy
Hence 1 man = 18/10 boys
25 men + 15 boys = (25 * 18/10) + 15 = 60
Now more work more days more boys less days1 * 60 * x = 2*18*15 or x = (2*18*15)/60 = 9 days
20. A can build up a structure in 8 days and B can break it in 4 days. A has worked for 4 days and then B joined to work with A for another 2 days only. In how many days will A alone build up the remaining part of the structure?
A. 8 days
B. 6 days
C. 4 days
D. 2 days
Answer
Explanation:
Part of structure built by A in a day = 1/8
Part of structure built by B in a day = 1/4
Part of structure built by A in 4 days = 4*1/8 = ½
Part of structure broken in the next 2 days after B joins A = 2*((1/4) – (1/8)) = ¼
A can build up the remaining 3/4th of the structure in 6 days.
21. A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C?
A. Rs. 375
B. Rs. 400
C. Rs. 600
D. Rs. 800
Answer
Explanation:
C's 1 day's work = (1/3) – [(1/6) + (1/8)] = [(1/3) – (7/24)] = (1/24) .
A's wages : B's wages : C's wages = (1/6) : (1/8) : (1/24) = 4 : 3 : 1.
C's share (for 3 days) = Rs. 3 x (1/24) x 3200 = Rs. 400.
22. If 10 workers can make 10 tables in 10 days, then how many days would it take for 5 workers to make 5 tables?
A. 1
B. 5
C. 10
D. 25
Answer
Explanation:
10 workers make 10 tables in 10 days.
1 worker makes 1 table in 10 days.
Similarly, 5 workers can make 5 tables in 10 days.
23. If daily wages of a man is double to that of a woman, how many men should work for 25 days to earn Rs.14400? Given that wages for 40 women for 30 days are Rs.21600.
A. 12
B. 14
C. 16
D. 18
Answer
Explanation:
Wages of 1 woman for 1 day =
Wages of 1 man for 1 day = 21600×2×40×30
Wages of 1 man for 25 days = 21600×2×25×40×30
Number of men = 14400(21600×2×2540×30)=144(216×5040×30)=1449=16
24. A can lay a railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in
A. 4
B. 9.6
C. 9
D. 10
Answer
Explanation:
Part of work completed by A and B in 4 days = 4*((1/16) + (1/12)) = 7/12
C can complete 5/12th of the work in 4 days
C can complete the whole job in 4÷(5/12) = 9.6 days.
25. A machine P can print one lakh books in 8 hours, machine Q can print the same number of books in 10 hours while machine R can print them in 12 hours. All the machines are started at 9 A.M. while chine P is closed at 11 A.M. and the remaining two machines complete work. Approximately at what time will the work (to print one lakh books) be finished?
A. 11:30 A.M.
B. 12 noon
C. 12:30 P.M.
D. 1:00 P.M.
Answer
Explanation:
(P + Q + R)'s 1 hour's work =(1/8) + (1/10) + (1/12) = (37/120)
Work done by P, Q and R in 2 hours = (37/120) x 2=(37/60)
Remaining work = 1 –(37/60)= (23/60) .
(Q + R)'s 1 hour's work =(1/10) +(1/12) = (11/60) .
Now, (11/60) work is done by Q and R in 1 hour.
So, (23/60) work will be done by Q and R in (60/11) x (23/60 ) = (23/11) hours equivalent to 2 hours.
So, the work will be finished approximately 2 hours after 11 A.M., i.e., around 1 P.M.
26. A can complete a work in 6 days and B can complete a work in 3 days. If A and B work together, in how many days can the work be completed?
A. 9 days
B. 4.5 days
C. 2 days
D. 1.5 days
Answer
Explanation:
Part of work completed by A in 1 day = 1/6
Part of work completed by B in 1 day = 1/3
Part of work completed by A and B together in a day = 1/6 +1/3 = ½
Days taken to complete the work = 2
