1. 4 men and 6 women complete a task in 24 days. If the women are at least half as efficient as the men, but not more efficient than the men, what is the range of the number of days for 6 women and 2 men to complete a task ?
A. 27 to 33.6 days
B. 30 to 36.6 days
C. 30 to 33.6 days
D. 24 to 27.6 days
E. None of these
Sol. 4m and 6w finish in 24 days.
In one day, 4m + 6w = 1/24 of task.
In these questions, just substitute extreme values to get the whole range
If a woman is half as efficient as man
4m + 3m = 1/24, 7m = 1/24, m = 1/168
6w + 2m = 3m + 2m = 5m, 5m will take 168/5 days = 33.6 days
If a woman is as efficient as a man
4m + 6w finish in 24 days
10m finish 1/24 of task in a day
6w + 2m = 8m, 8m will take 240/8 = 30 days to finish the task.
So, the range = 30 to 33.6 days. The new team will take 30 to 33.6 days to finish the task.
2. 30 soldiers can dig 10 trenches of size 8 × 3 × 3 ft in half a day working 8 hours per day. How many hours will 20 soldiers take to dig 18 trenches of size 6 × 2 × 2 ft working 10 hours per day?
A.6
B.3.6
C.36
D.18
E.None of these
Sol. Work involved in case 1: 8×3×3×10 cu ft.
This is done in 30×4 = 120 man hours.
So in one man hour, 8×3×3×10/120 = 6 cu ft of digging is done.
Work involved in case 2 = 18×6×2×2.
Man hours required = 18×6×2×2/6 = 18×2×2
Hours required = 18×2×2/20 = 3.6 hours
3. 15 women can complete 10% of the work in 7 days, 25 women worked for 31.5 days then what fraction of the work is remaining ?
A. 1/5
B. 1/6
C. 1/4
D. 1/3
E. None of these
Sol. 25 women complete the work in = (15*70)/25 = 42 days
25 women per day work = 1/42
25 women 31.5 day work = 31.5/42
Remaining work = (1 - 31.5/42) = 1/4.
4. 16 men and 12 women can complete a work in 8 days, if 20 men can complete the same work in 16 days, in how many days 16 women can complete the same piece of work ?
A. 8
B. 12
C. 10
D. 15
E. 9
Sol. Lets assume it take 'w' days for 1 women to complete the job.
Then, 16/(16*20) + 12/w = 1/8
w = 160 days
Now for 16 women it will be, = 160/16 = 10 days.
5. Arjun can complete a work in 60 days. Also if Arjun and Bibek work together, they complete the same work in 20 days. If both start work but Bibek works for only half a day, in how many days will both complete the work ?
A. 25
B. 30
C. 35
D. 20
E. None of these
Sol. Bibek’s 1 day’s work = 1/20 – 1/60 = 1/30
Now in 1day Bibek completes 1/30 of the work, so in half day he will complete 1/2 * 1/30 = 1/60 of the work
Now Arjun’s 1 day’s work is 1/60 and B’s 1/60
So their total 1 day’s work = 1/60 + 1/60 = 1/30
6. 8 men can complete a piece of work in 18 days, 18 women complete in 10 days while 6 children complete in 12 days. 4 children, 12 men and 20 women work for 2 days. If only children were to complete the remaining work in 1 day. How many children are required.
A. 36
B. 24
C. 18
D. Can’t determine
E. None of these
Sol. Sol. 8 M = 18 days
M = 18 × 8 = 144 days
W = 18 × 10 = 180 days
C = 6 × 12 = 72 days
Let work be 720 unit then
M = 5 unit daily
W = 4 unit daily
C = 10 unit daily
4 children, 12 men, 20 women = 40 + 60 + 80 = 180 unit × 2 = 360 unit
Rest 720 – 360 = 360 unit
So, no. of children who complete in 1 day = 360/10 = 36
7. In a regular week, there are 5 working days and for each day, the working hours are 8. A man gets Rs. 2.40 per hour for regular work and Rs. 3.20 per hours for overtime. If he earns Rs. 432 in 4 weeks, then how many hours does he work for?
A. 160
B. 175
C. 180
D. 195
E. None of these
Sol. Suppose the man works overtime for x hours.
Now, working hours in 4 weeks = (5 x 8 x 4) = 160.
160 x 2.40 + x X 3.20 = 432
3.20x = 432 - 384 = 48
8. P is twice as good a workman as Q and Q is twice as good a workman as R. If P and Q can together finish a piece of work in 4 days, then R can do it by himself in ?
A. 20
B. 24
C. 28
D. 32
E. None of these
Sol. R completes the work in 'y' days
Q completes the work in 'y/2' days
P completes the work in 'y/4' days
In 1 day P and Q working together,
= 4/y + 2/y
= 6/y
Thus, complete the work in 'y/6' days.
y/6 = 4
y = 24 days.
9. A can complete a piece of work in 4 days. B takes double the time taken by A, C takes double that of B, and D takes double that of C to complete the same task. They are paired in groups of two each. One pair takes two-thirds the time needed by the second pair to complete the work. Which is the first pair?
(a) A and B
(b) A and C
(c) B and C
(d) A and D
(e) C and D
Sol. Work done in one day by A, B and C are 1/4,1/8,1/16 and 1/32 respectively.
Using answer choices, we note that the pair of B and C does 3/16 of work in one day; the pair of A and D does 1/4+1/32=9/32 of work in one day
Hence, A and D take 32/9 days
B and C take 16/3=32/6 days
Hence, the first pair must comprise of A and D.
10. X and Y can do a piece of work in 20 days and 30 days. Both starts the work together for some time, but Y leaves the job 5 days before the work is completed. Find the time in which work is completed ?
A. 7 days
B. 12 days
C. 14 days
D. 16 days
E. None of these
Sol. Together they can finish the job in,
= 1/(1/20 + 1/30)
= 12 days
X works alone for 5 days, thus completes, = 5/20 = 1/4th work
Work to be completed by both working togeher = 1- 1/4 = 3/4th
Time taken for that = 12*(3/4) = 9 days.
Thus, total time take to complete the work is = (9 + 5) = 14 days.
Important Note:
To receive the fastest updates on Bank Exams like IBPS, SBI, RBI, IPPB, etc. as well as all other ongoing as well as forthcoming exams, kindly subscribe to our website. All you have to do is enter your email in the pop-up that appears on the website when you first enter it on the home page. Once you’re subscribed, you will receive all the latest updates concerning all competitive exams.
For more Updates & Notifications for bank exams like SBI PO, SBI CLERK, IBPS PO, IBPS RRB, IBPS CLERK, IBPS SO, NIACL, SSC CHSL, SSC CGL etc. like our facebook page at :
0 comments:
Post a Comment