An empty pool being filled with water at a constant rate takes 8 hrs to fill to 3/5 of its capacity. How much more time will it take to finish filling the pool?
A. 5 hr 30 min
B. 5 hr 20 min
C. 4 hr 48 min
D. 3 hr 12 min
E. 2 hr 40 min
[spoiler]OA - B(can some one explain)[/spoiler]
Algebra : Applied Problem
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- anirudhbhalotia
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The tank is already fill to (3/5) of its capacity.anirudhbhalotia wrote:An empty pool being filled with water at a constant rate takes 8 hrs to fill to 3/5 of its capacity. How much more time will it take to finish filling the pool?
A. 5 hr 30 min
B. 5 hr 20 min
C. 4 hr 48 min
D. 3 hr 12 min
E. 2 hr 40 min
Therefore, empty space in the tank = (1- 3/5) = (2/5) of its capacity.
Now, to fill to (3/5) of its capacity time required = 8 hrs
Thus, to fill to (2/5) of its capacity time required = [8*(2/5)]/(3/5) = (8*2)/3 hrs = (5 + 1/3) hrs = 5 hrs 20 minutes
The correct answer is B.
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X3/5=8 (X is time taken for full capacity)anirudhbhalotia wrote:An empty pool being filled with water at a constant rate takes 8 hrs to fill to 3/5 of its capacity. How much more time will it take to finish filling the pool?
A. 5 hr 30 min
B. 5 hr 20 min
C. 4 hr 48 min
D. 3 hr 12 min
E. 2 hr 40 min
[spoiler]OA - B(can some one explain)[/spoiler]
X=40/3
40/3 * 2/5 = 80/15 = 5 hrs, 20 min
- anirudhbhalotia
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Not getting the logic.
Lets say the capacity is 100.
So it takes 8 hrs to fill, 3/5 of 100...which is 60.
How long will it take to fill remaining 40?
Lets say the capacity is 100.
So it takes 8 hrs to fill, 3/5 of 100...which is 60.
How long will it take to fill remaining 40?
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To fill 60 it takes 8 hrsanirudhbhalotia wrote:Lets say the capacity is 100.
So it takes 8 hrs to fill, 3/5 of 100...which is 60.
How long will it take to fill remaining 40?
To fill 1 it will take (8/60) hrs
To fill 40 it will take (8*40)/60 hrs
(8*40)/60 hrs = (16/3) hrs = (5 + 1/3) hrs = 5 hrs + (1/3) hrs = 5rs + 20 minutes = 5 hrs 20 minutes
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- anirudhbhalotia
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Gotcha!Anurag@Gurome wrote:To fill 60 it takes 8 hrsanirudhbhalotia wrote:Lets say the capacity is 100.
So it takes 8 hrs to fill, 3/5 of 100...which is 60.
How long will it take to fill remaining 40?
To fill 1 it will take (8/60) hrs
To fill 40 it will take (8*40)/60 hrs
(8*40)/60 hrs = (16/3) hrs = (5 + 1/3) hrs = 5 hrs + (1/3) hrs = 5rs + 20 minutes = 5 hrs 20 minutes
This is what I was trying to do...but was trying to do in terms of hours and not how much to fill.
Thanks Anurag!
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We can plug in a value for the pool.anirudhbhalotia wrote:An empty pool being filled with water at a constant rate takes 8 hrs to fill to 3/5 of its capacity. How much more time will it take to finish filling the pool?
A. 5 hr 30 min
B. 5 hr 20 min
C. 4 hr 48 min
D. 3 hr 12 min
E. 2 hr 40 min
[spoiler]OA - B(can some one explain)[/spoiler]
Let pool = 40 liters.
Work completed in 8 hours = (3/5)*40 = 24 liters.
Thus, rate = w/t = 24/8 = 3 liters per hour.
Work remaining = 40-24 = 16 liters.
Time to finish = w/r = 16/3 = 5 hours, 20 min.
The correct answer is B.
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We need to find the time to fill the remaining 2/5 of the pool. Thus, we can use the following proportion:anirudhbhalotia wrote:An empty pool being filled with water at a constant rate takes 8 hrs to fill to 3/5 of its capacity. How much more time will it take to finish filling the pool?
A. 5 hr 30 min
B. 5 hr 20 min
C. 4 hr 48 min
D. 3 hr 12 min
E. 2 hr 40 min
8/(3/5) = x/(2/5)
40/3 = 5x/2
15x = 80
x = 80/15 = 16/3 = 5 1/3 hr = 5 hr 20 min
Alternate Solution:
Let's assume the capacity of the pool is 5 gallons. Since it takes 8 hours to fill 3/5 x 5 = 3 gallons, the pool is filled at a rate of 3/8 gallons per hour. Since 3 gallons of the pool is already filled, the remaining 5 - 3 = 2 gallons will be filled in 2 x (8/3) = 16/3 = 5 1/3 hours; or 5 hours and 20 minutes.
Answer: B
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We know it takes 8 hours to fill to 3/5 of its capacity.An empty pool being filled with water at a constant rate take 8 hours to fill to 3/5 of its capacity. How much more time will it take to finish filling the pool ?
A. 5hr 30 min
B. 5hr 20 min
C. 4hr 48 min
D. 3hr 12 min
E. 2hr 40 min
We want to know how long it will take to fill the remaining 2/5 of capacity.
IMPORTANT: 2/5 is 2/3 as big as 3/5
So, if it takes 8 hours to fill 3/5 of the pool, then the time to fill 2/5 of the pool = (2/3)(8) hours = 16/3 hours = 5 1/3 hours = [spoiler]5 hours and 20 minutes = B[/spoiler]
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Brent
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Here's a slightly different approach.anirudhbhalotia wrote:An empty pool being filled with water at a constant rate takes 8 hrs to fill to 3/5 of its capacity. How much more time will it take to finish filling the pool?
A. 5 hr 30 min
B. 5 hr 20 min
C. 4 hr 48 min
D. 3 hr 12 min
E. 2 hr 40 min
[spoiler]OA - B(can some one explain)[/spoiler]
It takes 8 hours to fill to 3/5 of its capacity.
So, in 1/3 the time, we'll fill 1/3 as much. In other words, in 8/3 hours we can fill 1/5 of the pool.
We want to know how long it will take to fill 2/5 of the pool.
So, it will take twice as long as 8/3 hours.
This means that, the time to fill 2/5 of the pool = 2(8/3)
= 16/3 hours
= 5 1/3 hours
= 5 hours and 20 minutes
= B
Cheers,
Brent