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# Reservoir

31 replies to this topic

### #1 rookie1ja

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Posted 30 March 2007 - 03:48 PM

Filling the Pool - Back to the Cool Math Games
A swimming pool has four faucets. The first can fill the entire pool with water in two days, the second – in three days, the third – in four days, and the last one can fill the pool in 6 hours.
How long will it take to fill the pool using all 4 faucets together?

This old topic is locked since it was answered many times. You can check solution in the Spoiler below.
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### #2 natterbox

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Posted 28 April 2007 - 06:29 PM

i divided them all by 4 and added them up to get 2 days and 7 hours
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### #3 Stephanie

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Posted 03 June 2007 - 03:11 PM

I did it in the same way as rookie1ja, and got approximately 4 hrs and 44 minutes.. little bit less, actually.

How did you get that solution with more than 2 days?

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### #4 larryhl

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Posted 05 June 2007 - 08:55 PM

natterbox, if all 4 taps are working together, you need to get a time less than 6 hours >< tap 4 can't do the whole job faster than all 4 working together.

as a decimal, the time is approximately 4.72 hours.
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### #5 dak1530

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Posted 27 June 2007 - 03:58 PM

i came up with 4.73 hrs or 4 and 44 minutes
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### #6 lukegaru

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Posted 03 July 2007 - 08:50 PM

4.72hours
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### #7 savagegamer90

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Posted 03 July 2007 - 08:58 PM

I got 4.72 hours as well
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### #8 lucid

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Posted 07 July 2007 - 09:43 PM

The answer is precisely 12/61 days.

A = 1/2 (reservoirs/day)
B = 1/3
C = 1/4
D = 4

(A + B + C + D) * Time = 1 (Time is in days. A, B, C, and D are in reservoirs per day.)
(1/2 + 1/3 + 1/4 + 4) * Time = 1
(61 / 12) * Time = 1
Time = 12 / 61 days (~ 4.72 hours)
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### #9 tealuvr104

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Posted 29 August 2007 - 11:30 PM

2 days = 48 hours = x
3 days = 72 hours = y
4 days = 96 hours = z
6 hours = a

(x + y)/2= 60
(60+ z)/2=78
(78+6)/2=42

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### #10 PMitra

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Posted 03 September 2007 - 11:54 AM

First of all we will calculate per hour work done by each tap like-

1st tap will fill the reservior by 1/48 in an hour.
2nd tap will fill it 1/72
3rd will fill 1/96 part of the reservior in an hour.
and 4th will fill 1/6

now sum of all four taps if all are open simultaneously will be- 61/288

which gives the answer as- all four taps if open simultaneously will put the reservior in eq state in 4 hours 43 minutes and 2** seconds... ( Is that okay )
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