The water level in a rectangular swimming pool measuring 60 : Problem Solving (PS)

subhashghosh

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20 Apr 2011, 18:35

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Volume removed = 60 * 25 * 6/12 = 30 * 25 = 750 cu. ft

So Gallons to be removed = 750 * 7.5 = 625 * 9 = 5625 Gallons

Answer - E

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21 Apr 2011, 05:22

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Volume of the swimming pool where water needs to be lowered = 60 * 25 * 6/12 = 750 cu. ft
Water in Gallons that needs to be removed = 750 * 7.5 = 5625 Gallons
OA is E

liko21

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10 Apr 2012, 09:42

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I don't get it....how can we figure out the answer if we don't have th third dimension of the pool?

:shock:

Bunuel

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10 Apr 2012, 10:28

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liko21

I don't get it....how can we figure out the answer if we don't have th third dimension of the pool?

:shock:

We don't need the third dimension of the pool.

We need 3 dimensions of the water that must be removed, which are 60, 25 and 1/2 feet (6 inches).

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10 Apr 2012, 18:49

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Bunuel

tonebeeze

The water level in a rectangular swimming pool measuring 60 feet by 25 feet is to be lowered by 6 inches. How many gallons of water must be removed? (1 cu ft = 7.5 gallons)

a. 100
b. 250
c. 750
d. 1200
e. 5625

6 inches = 1/2 feet (there are 12 inches in a foot.), so 60*25*1/2=750 feet^3 of water must be removed, which equals to 750*7.5=5625 gallons.

Answer: E.

Can you explain why you multiply by 1/2? The problem doesn't say that you lower the pool by half but only by 6 inches. I would think that you would multiply by 1/2 if the question asked to lower the pool by 12.5 feet. What am i missing.
Thank you very much!

Bunuel

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11 Apr 2012, 00:49

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bohdan01

Bunuel

tonebeeze

The water level in a rectangular swimming pool measuring 60 feet by 25 feet is to be lowered by 6 inches. How many gallons of water must be removed? (1 cu ft = 7.5 gallons)

a. 100
b. 250
c. 750
d. 1200
e. 5625

6 inches = 1/2 feet (there are 12 inches in a foot.), so 60*25*1/2=750 feet^3 of water must be removed, which equals to 750*7.5=5625 gallons.

Answer: E.

Can you explain why you multiply by 1/2? The problem doesn't say that you lower the pool by half but only by 6 inches. I would think that you would multiply by 1/2 if the question asked to lower the pool by 12.5 feet. What am i missing.
Thank you very much!

Two dimensions (60 feet and 25 feet) are given in feet, so we should express the third dimension in feet too: 6 inches = 1/2 feet.

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11 Apr 2012, 18:12

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Bunuel

bohdan01

Bunuel

The water level in a rectangular swimming pool measuring 60 feet by 25 feet is to be lowered by 6 inches. How many gallons of water must be removed? (1 cu ft = 7.5 gallons)

a. 100
b. 250
c. 750
d. 1200
e. 5625

6 inches = 1/2 feet (there are 12 inches in a foot.), so 60*25*1/2=750 feet^3 of water must be removed, which equals to 750*7.5=5625 gallons.

Answer: E.

Can you explain why you multiply by 1/2? The problem doesn't say that you lower the pool by half but only by 6 inches. I would think that you would multiply by 1/2 if the question asked to lower the pool by 12.5 feet. What am i missing.
Thank you very much!

Two dimensions (60 feet and 25 feet) are given in feet, so we should express the third dimension in feet too: 6 inches = 1/2 feet.[/quote]

Thanks. To follow up, how do you know what the third dimension is? It could be 10 feet where 6 inches would be 6/120 or it could be 1 foot where 6 inches would be 1/2. I assume you mention the third dimension since we are talking about the volume, but how can we assume anything about the third dimension?

Bunuel

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12 Apr 2012, 00:20

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bohdan01

Thanks. To follow up, how do you know what the third dimension is? It could be 10 feet where 6 inches would be 6/120 or it could be 1 foot where 6 inches would be 1/2. I assume you mention the third dimension since we are talking about the volume, but how can we assume anything about the third dimension?

It seems that you misunderstood the question: questions is simple saying that 60*25*1/2=750 feet^3 of water is removed and asks to calculate how much is that in gallons.

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05 Dec 2012, 11:33

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The problem should also give relationship between feet and inch
Brother Karamazov

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12 Sep 2013, 03:33

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Tricky question! What would be the difficulty level of this question bunuel

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12 Sep 2013, 03:38

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fozzzy

Tricky question! What would be the difficulty level of this question bunuel

Look at the statistics in the original post: 45% answered incorrectly, so I'd say the difficulty level is ~650.

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12 Feb 2014, 16:35

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Bunuel

fozzzy

Tricky question! What would be the difficulty level of this question bunuel

Look at the statistics in the original post: 45% answered incorrectly, so I'd say the difficulty level is ~650.

I don't think that in the real test they won't give you the relation feet inches. Even less now considering how many non american citizens are taking the test

Just a quick reflection
Cheers!
J

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04 Apr 2016, 18:06

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tonebeeze

The water level in a rectangular swimming pool measuring 60 feet by 25 feet is to be lowered by 6 inches. How many gallons of water must be removed? (1 cu ft = 7.5 gallons)

A. 100
B. 250
C. 750
D. 1200
E. 5625

I believe the question is not properly written.
there is no info given about the measures of inches to feet
since I live in US, i know about it..but people from EU definitely have no idea about the conversion from inches to ft.
12 inch = 1ft
suppose the pool is 1ft deep. then we have 60x25x1 = 1500 cu ft.
now..we need to lower 6 inches, which means we have 0.5 ft.
60x25x0.5 = 30x25 = 750 cu ft.
so we need to take out 750 cu ft.
750 cu ft * 7.5 = 75^2.
since we have 5 in the end, only E works.

E

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13 Jul 2018, 14:16

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tonebeeze

The water level in a rectangular swimming pool measuring 60 feet by 25 feet is to be lowered by 6 inches. How many gallons of water must be removed? (1 cu ft = 7.5 gallons)

A. 100
B. 250
C. 750
D. 1200
E. 5625

Using the fact that 6 in = 1/2 ft, the amount of water to be removed is 60 x 25 x 1/2 = 750 cu ft. Since 1 cu ft = 7.5 gallons, the number of gallons of water that must be removed is 750 x 7.5 = 5625.

Answer: E

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01 Sep 2019, 11:17

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it could have been nice to mention that 6in = 0.5ft for those using the metric system

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