# Quantitative Aptitude: Time and Work Set 22

1. A water tank holds 50 gallons of water.Its inlet is 3.5 inch diameter and fills the tank at 2.5 gallons/ min. The outlet of the tank is twice the diameter of the inlet. How many minutes will it take to empty the tank if the inlet is closed, when the tank is fulled the outlet is opened?
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Option A
Since the ratio of flow is proportional to the diameter
=>outlet flow = 2* 2.5 = 5 gallons/min
So time taken by outlet pipe to be empty the tank = 50/5 = 10 min

2. Three pipes 1,2 and 3 can fill the tank in 30, 40 and 60 minutes respectively. If all the three pipes started to fill the tank in same time and the pipe 3 is closed before 12 minutes of the tank is filled. In what time the tank will be filled?
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Option D
Work done in last 12 minutes= 12( 1/ 30 + 1/40) = 7/10
remaining work = 1-7/10 = 3/10
( 1+ 2+ 3) pipes one minute work = 1/30 +1/40 + 1/60 = 9/120 = 3/40
So total number of minutes = 3/10 / 3/40 + 12=16 minutes.

3. Two pipes A and B can fill an empty tank in 16 hrs 24hrs respectively. Raja opens these two pipes at a time. After 8/3 hrs he comes back and sees there was a leak in the tank. He closed the leakage and so tank took 48/5 hours to be filled completely after closing the leak.Find at what time the leakage will empty the filled tank?

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Option A
let the leak can empty the tank in x hrs.
So 8/3 hrs work of two pipes and leakage = ( 1/16 +1/24 – 1/x) *8/3
=5/18 – 8/3x
So remaining part= 1- 5/18 -8/3x= 13/18 + 8/3x
=>x=9.6 hrs.

4. A pipe can fill the tank which is three time faster than another fill pipe. and 16 minutes less that one . Find when will the cistern will be filled if both the pipes are opened together?
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Option B
Let the first pipe takes x minutes to fill the cistern.
Second pipe takes 3x minutes to fill the cistern.
=>3x-x =16
=>x=8 minutes=>3x= 3*8 = 24 minutes
So both the pipe can fill 24* 8 / 24+8 = 6 minutes

5. A tank has two inlet pipes which fill the tank 24 minutes 30 minutes respectively and also there will be n outlet pipe.When all the three pipes are opened together it takes 40 minutes to fill the empty tank. How long will the outlet pipe take to empty the tank?
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Option C
Let the outlet pipe can empty the tank in x minutes.
=>1/24 + 1/30 – 1/x= 1/40 => x=20 minutes.

6. A tank is 14m long and 8m wide. at what speed should water run through a rectangular pipe 10cm broad and 8 cm deep so that in 6hours 18 minutes water level in the tank raised in 9m?
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Option D
Volume of water flown = 14* 8* 9 =1008 m3
Let the speed of the water be x km/hr
=>( x * 1000 * 63/10 ) * 10/100 * 8/100 = 1008
=>x=20km/hr

7. Two pipes can fill the tank in 20 hours and 32 hours respectively. a third pipe can empty the tank in 64 hours. If all the pipes are opened at a time the how much time will the tank takes to fill?
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Option B
Part of the tank filled in 1 hr = 1/20 + 1/32- 1/64 = 42/320
=>tank be filled in 320/42 = 8 hrs (approx)

8. Three pipes A,B and C can fill an empty tank in 8 hrs, 12hrs, and 16 hrs respectively. They start filling together the tank.After 2hours pipe C gets closed and another two pipes continue to fill the tank.What is the total time the tank will be filled?
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Option B
Ratio of efficiency 1/8 :1/12:1/16
=12:8:6
Total work =96 ( LCM8,12,16)work done in 2 hrs= 2( 12+8+6)=52 units
Remaining work= 96-52= 44 units
So required time = 2+44/10 = 6.4 hours.

9. Two pipes can fill a tank in 30 hours and 40 hours respectively.While the third pipe can empty in 60 hours. If all the pipes are opened simultaneously, the empty tank will be filled in how much time?

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Option C
Total work done in one hour by all the pipes= 1/30 +1/40 -1/60
=5/120 =1/24
=>In 24 hours the tank wil be filled.

10. In a tank, water poured by pipe 1 reached 50% of the maximum marked level in one hour. Pipe 2 poured water and it reaches 12% of the remaining maximum level in the next hour.If the maximum capacity of the tank is 240ltr,Then how much water poured by pipe 2 in second hour?
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Option E
Maximum level of water = 240ltr
Pipe poured in first hour = 50% of 240ltr=120ltr
Remaining water to be poured= 240 – 120 = 120ltr
Pipe poured water in second hour =12% of 120 ltr = 14.4ltr