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A pump started filling an empty pool with water and continued at a con
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29 Jan 2022, 06:34
29 Jan 2022, 06:34
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Question Stats:
69% (02:00) correct
30% (02:54) wrong based on 13 sessions
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A pump started filling an empty pool with water and continued at a constant rate until the pool was full. At noon the pool was 1/3 full, and \(1\frac{1}{4}\) hours later it was 3/4 full. What was the total number of hours that it took the pump to fill the pool?
A. \(2\frac{1}{3}\)
B. \(2\frac{2}{3}\)
C. 3
D. \(3\frac{1}{2}\)
E. \(3\frac{2}{3}\)
A. \(2\frac{1}{3}\)
B. \(2\frac{2}{3}\)
C. 3
D. \(3\frac{1}{2}\)
E. \(3\frac{2}{3}\)
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Re: A pump started filling an empty pool with water and continued at a con
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29 Jan 2022, 06:45
29 Jan 2022, 06:45
2
Carcass wrote:
A pump started filling an empty pool with water and continued at a constant rate until the pool was full. At noon the pool was 1/3 full, and \(1\frac{1}{4}\) hours later it was 3/4 full. What was the total number of hours that it took the pump to fill the pool?
A. \(2\frac{1}{3}\)
B. \(2\frac{2}{3}\)
C. 3
D. \(3\frac{1}{2}\)
E. \(3\frac{2}{3}\)
A. \(2\frac{1}{3}\)
B. \(2\frac{2}{3}\)
C. 3
D. \(3\frac{1}{2}\)
E. \(3\frac{2}{3}\)
For this type of question, I like to assign a "nice value" to the job.
In this case we're looking for a number that works well with 1/3, 3/4 and even 1 1/4
So, let's say the pool has a capacity of 60 liters.
At noon the pool was 1/3 full, . . .
1/3 of 60 liters = 20 liters
So, at 12:00pm, the pool contained 20 liters of water
. . . and 1 1/4 hours later it was 3/4 full.
1 1/4 hours = 1.25 hours = 75 minutes.
3/4 of 60 liters = 45 liters
So, at 1:15pm, the pool contained 45 liters of water
What was the total number of hours that it took the pump to fill the pool?
45 liters - 20 liters = 25 liters
So, in 1.25 hours, 25 liters of water was added to the pool
Rate = output/time
So, the rate at which water is added to the pool = (25 liters)/(1.25 hours) = 20 liters per hour
Time = output/rate
So, at a rate of 20 liters per hour, the time it takes to fill the 60 liter pool = 60/20 liters = 3 hours
Answer: C
Re: A pump started filling an empty pool with water and continued at a con
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06 Feb 2022, 00:22
06 Feb 2022, 00:22
1
Even Better way that i found - Time taken to fill 5/12 of the Tank = 75 MINS - Calculate the time taken for 12/12ths of the tank - Answer 180 Mins.
