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- Question
Four pipes P,Q, R and S can fill a cistern in 20,25, 40 and 50 hours respectively.The first pipe P was opened at 6:00 am, Q at 8:00 am, R at 9:00 am and S at 10:00 am. when will the Cistern be full?
Options- A. 4:18 pm
- B. 3:09 pm
- C. 12:15 pm
- D. 11:09 am
- Correct Answer
- 3:09 pm
ExplanationEfficiency of P= 100/20= 5% per hour
Efficiency of Q= 100/25= 4% per hour
Efficiency of R= 100/40= 2.5% per hour
Efficiency of S=100/50= 2% per hour
Cistern filled till 10 am by P, Q and R
Thus, at 10 am pipe P,Q and R filled 30.5% of the cistern.
Rest of cistern to be filled = 100 - 30.5 = 69.5%
Now, the time taken by P,Q,R and S together to fill the remaining capacity of the cistern
= 69.5 / (5+4+2.5+2) = 5 Hours and 9 minutes(approx).
Therefore, total time =4 hrs + 5hrs 9 mins = 9 hrs and 9 mins
It means cistern will be filled up at 3:09 pm
- 1. M can complete a piece of work in 10 days. N is 33.33% less efficient than M. calculate the number of days required to both to complete the work?
Options- A. 6 days
- B. 8 days
- C. 11 days
- D. 13 days Discuss
- 2. 12 men complete a work in 9 days. After they have worked for 6 days, 4 more men join them. How many days will they take to complete the remaining work ?
Options- A. 2 days
- B. 2.5 days
- C. 2.25 days
- D. 3 days Discuss
- 3. 4 men and 6 women can complete a work in 8 days, while 3 men and 7 women can complete it in 10 days. In how many days will 10 women complete it ?
Options- A. 40 days
- B. 36 days
- C. 32 days
- D. 34 days Discuss
- 4. 6 men can complete a piece of work in 12 days. 8 women can complete the same piece of work in 18 days whereas 18 children can complete the piece of work in 10 days. 4 men, 12 women and 20 children work together for 2 days. If only men were to complete the remaining work in 1 day how many men would be required totally?
Options- A. 38
- B. 72
- C. 36
- D. 76 Discuss
- 5. If 10 men take 15 days to complete a work. In how many days will 37 men complete the work?
Options- A. 3 days
- B. 4 days
- C. 5 days
- D. 6 days Discuss
- 6. P is 30% more efficient than Q. How much time will they, working together, take to complete a job which P alone could have done in 23 days?
Options- A. 16 days
- B. 13 days
- C. 15 days
- D. 12 days Discuss
- 7. 9 men and 12 boys finish a job in 12 days, 12 men and 12 boys finish it in 10 days. 10 men and 10 boys shall finish it in how many days ?
Options- A. 15 days
- B. 11 days
- C. 14 days
- D. 12 days Discuss
- 8. A contractor undertake to finish a certain work in 124 days and employed 120 men. After 64 days, he found that he had already done 2/3 of the work. How many men can be discharged so that the work may finish in time ?
Options- A. 64
- B. 62
- C. 58
- D. 56 Discuss
- 9. Three athletes can complete one round around a circular field in 16, 24 and 36 min respectively. They start running together at same instant then after how much time they will meet to each other for first time ?
Options- A. 2 hrs 24 min
- B. 2 hrs 44 min
- C. 1 hrs 24 min
- D. 1 hrs 24 min Discuss
- 10. A contractor undertook a project to complete it in 20 days which needed 5 workers to work continuously for all the days estimated. But before the start of the work the client wanted to complete it earlier than the scheduled time, so the contractor calculated that he needed to increase 5 additional men every 2 days to complete the work in the time the client wanted it: If the work was further increased by 50% but the contractor continues to increase the 5 workers o every 2 days then how many more days are required over the initial time specified by the client.
Options- A. 1 day
- B. 2 days
- C. 5 days
- D. None of these Discuss
Time and Work problems
Search Results
Correct Answer: 6 days
Explanation:
M = 10 days
The ratio of efficiency of M & N are 3 : 2
Hence, the time rquired for N alone = 15 days
=> Required time taken t=by both to complete the work = M x N / M + N
= 10 x 15/ 10 + 15
= 150/25
= 6 days.
Correct Answer: 2.25 days
Explanation:
1 man's 1 day work = 1/108
12 men's 6 day's work = 1/9 x 6 = 2/3
Remaining work = 1 - 2/3 = 1/3
16 men's 1 day work = 1/108 x 16 = 4/27
4/27 work is done by them in 1 day.
1/3 work is done by them in 27/4 x 1/3 = 9/4 days.
Correct Answer: 40 days
Explanation:
Let 1 man's 1 day work = x and 1 woman's 1 day work = y.
Then, 4x + 6y = 1/8 and 3x + 7y = 1/10
Solving these two equations, we get:
x = 11/400 and y = 1/400
10 woman's 1 day work = (1/400 x 10) = 1/40.
Hence, 10 women will complete the work in 40 days.
Correct Answer: 36
Explanation:
Given 4men, 12 women and 20 children work for 2 days.
Workdone for 2 days by 4men, 12 women and 20 children =
Therefore, remaining work = 1 - =
To complete the same work by only men in 1 day,
We know that M1 x D1 = M2 x D2
Here M1 = 6 , D1 = 12 and M2 = M , D2 = 1
12 x 6 = M x 1
=> M = 12 x 6 = 72
=> But the remaining work = 1/2
Men required => 1/2 x 72 = 36
Only men required to Complete the remaining work in 1 day = 36.
Correct Answer: 4 days
Explanation:
Given 10 men take 15 days to complete a work
=> Total mandays = 15 x 10 = 150
Let the work be 150 mandays.
=> Now 37 men can do 150 mandays in 150/37 =~ 4 days
Correct Answer: 13 days
Explanation:
Ratio of times taken by P & Q = 100 : 130 = 10:13
Let Q takes x days to do the work
Then, 10:13 :: 23:x
=> x = 23x13/10
=> x = 299/10
P's 1 day's work = 1/23
Q's 1 day's work = 10/299
(P+Q)'s 1 day's work = (1/23 + 10/299) = 23/299 = 1/13
Hence, P & Q together can complete the work in 13 days.
Correct Answer: 12 days
Explanation:
9M + 12B ----- 12 days ...........(1)
12M + 12B ------- 10 days........(2)
10M + 10B -------?
108M + 144B = 120M +120B
24B = 12M => 1M = 2B............(3)
From (1) & (3)
18B + 12B = 30B ---- 12 days
20B + 10B = 30B -----? => 12 days.
Correct Answer: 56
Explanation:
Days remaining 124 ? 64 = 60 days
Remaining work = 1 - 2/3 = 1/3
Let men required men for working remaining days be 'm'
So men required = (120 x 64)/2 = (m x 60)/1 => m = 64
Men discharge = 120 ? 64 = 56 men.
Correct Answer: 2 hrs 24 min
Explanation:
Given that three athletes can complete one round around a circular field in 16, 24 and 36 min respectively.
Now, required time after which they met for the first time = LCM of (16, 24 & 36) min
Now, LCM of 16, 24, 36 = 144 minutes = 2 hrs 24 min.
Correct Answer: 2 days
Explanation:
Total work = 100+50 = 150man-days
In 8 days 100 man-days work has been completed. Now on 9th and 10th day there will be 25 workers. So in 2 days they wll complete additional 50 man- days work. Thus the work requires 2 more days.
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