PE 4 - Time & Work | Arithmetic - Time & Work
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A piece of work can be completed by 15 men in a certain number of days. If there were three more men the work will be completed one day earlier. In how many days can 45 men complete the same work?
Solution
Discuss
ReportCertain number of men can complete a work in 16 days. They start working together. Starting from second day a man leaves at the start of the day. The work now gets completed at the end of the day when the last person works. How many men were there at the start.
A and B can do a certain piece of work in 18 days, B and C can do it in 12 days and C and A can do it in 24 days. How long would each take separately to do it (in days resp)?
- (a)
144, 115, 95
- (b)
144/7, 110, 80
- (c)
114/5, 120, 45
- (d)
None of these
A pipe can fill a tank in 10 minutes and another pipe can fill it in 15 minutes. A person opens both the pipes simultaneously. When the tank should have been full, he finds that the drain pipe is open. He then closes the drain pipe and after six minutes, the tank is full. In how much time can the drain pipe empty the tank?
- (a)
5 mins
- (b)
8 mins
- (c)
4 mins
- (d)
3 mins
- (e)
6 mins
To completely fill a half filled tank, tap X is opened and the tank will be fully filled in 30 hours. But after 6 hours, the water supply was cut-off. Before the supply resumes, exactly half of the water in the tank has been used up. How much time would it take now to fill the tank completely?
- (a)
12 hours
- (b)
15 hours
- (c)
42 hours
- (d)
24 hours
- (e)
20 hours
An inlet tap can fill a tank in 20 hours. This tap was opened at time zero, but after 4 hours (t = 4), a leak developed at the bottom. After 8 hours (t = 8), the cross section of the leak became triple because of which, it took 30 hours to fill the tank. How much time will it take to fill the tank if the cross section of the hole does not change at t = 8?
[Type in your answer as the nearest possible integer in seconds.]
The amount of work done by a man on nth day after starting a piece of work is n times the amount of work that can be done on the first day. If 15 men start the work, it can be completed in 7 days. How many men should work if the work has to be completed in 3 days?
A man started a piece of work on the first day. The second day, one more person joined him. The next day, one more person joined. Everyday, one new person joined until the work got completed. Also every day the efficiency of all men doubled as compared to previous day. If the work was completed in 5 days, how many days would 43 men take to complete the same work, given that they worked regularly and with the same efficiency on all days as on day 1?
- (a)
days
- (b)
days
- (c)
3 days
- (d)
2 days
- (e)
5 days
Three cooks together have to make 80 samosas. While working together, they can make 20 pieces per minute. The first cook starts the work alone and makes 20 pieces while working for more than three minutes. The remaining part of the work is done by the second cook and the third cook, working together. If they take a total of 8 minutes to prepare 80 samosas, then how many minutes will the first cook take alone to cook 160 samosas?
- (a)
32
- (b)
16
- (c)
24
- (d)
80
- (e)
40
Consider two tanks - T1 & T2 such that the volume of T2 is twice that of T1. T1 is fitted with 1 pipe A of circular cross-section, whereas T2 has 3 pipes – P, Q & R of circular cross-sections. The ratio of diameters of P, Q & R is 1 : 2 : 3. P’s cross-sectional area is 2 times A’s cross-sectional area. A takes 56 min to fill T1. Find the time taken to fill T2, if all the 3 pipes are opened.
- (a)
5 minutes
- (b)
4.5 minutes
- (c)
4 minutes
- (d)
None of these