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OG 2018 problem solving #89

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by Fab » Sat Nov 08, 2008 8:15 am

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Answers

A

B

C

D

E

Stats

Difficulty—

A glass was filled with 10 ounces of water, and 0.01 ounce of the water evaporated each day during a twenty-day period. What percent of the original amount of water evaporated during this period?

A. 0.002%
B. 0.02%
C. 0.2%
D. 2%
E. 20%

D
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by dmateer25 » Sat Nov 08, 2008 8:24 am
After 20 Days: .01*20=.20 ounces evaporated

.20/10 = .02 * 100 = 2%

IMO D
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by cramya » Sat Nov 08, 2008 9:29 am
A glass was filled with 10 ounces of water, and 0.01 ounce of the water evaporated each day during a twenty-day period. What percent of the original amount of water evaporated during this period?

A. 0.002%
B. 0.02%
C. 0.2%
D. 2%
E. 20%

In 20 days 20*.01 = .2

% evaporated = .2/10 * 100 = .2*10 = 2 %
D)
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by sgarnepudi » Sat Nov 08, 2008 9:07 pm
It is 2% (D) .. 0.01*20 = 0.20. Lets assume its 1 ounce. 1.00-0.20 = 20% now divide by 10 we get 2%. Is the answer correct?
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by Jeff@TargetTestPrep » Thu Apr 30, 2015 10:30 am
Fab wrote:Q24:
A glass was filled with 10 ounces of water, and 0.01 ounce of the water evaporated each day during a twenty-day period. What percent of the original amount of water evaporated during this period?

A. 0.002%
B. 0.02%
C. 0.2%
D. 2%
E. 20%
Solution:

We are given that 0.01 ounces of water evaporated EACH DAY. Furthermore, we know that this process happened over a 20-DAY PERIOD. To calculate the total amount of water that evaporated during this time frame we need to multiply 0.01 by 20. This gives us:

0.01 x 20 = 0.2 ounces

Finally, we are asked for "What percent" of the original amount of water evaporated during this period. To determine this percentage, we have to make sure we translate the expression correctly. We can translate it to:

(Amount Evaporated/Original Amount) x 100%

(0.2/10) x 100%

(2/100) x 100% = 2%

Answer D

Jeffrey Miller
Head of GMAT Instruction
[email protected]

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Re: OG 2018 problem solving #89

by [email protected] » Tue Apr 20, 2021 8:33 pm
Hi All,

We’re told that a 10 total ounces of water is evaporated at a rate of 0.01 ounces of water each day for 20 days. We’re asked what PERCENT of the water EVAPORATED during those 20 days.

You should notice that the 5 answers all involve percentages AND decimals (so this is a ‘decimal shift’ question). We’ll have to be really careful about how we approach our calculations, since if we make a little mistake, then we’ll choose one of the wrong answers and not even know it.

First, (0.01 ounces/day)(20 days) = .2 ounces of water evaporated

.2/10 = 2/100 = 2%

Final Answer: D

GMAT Assassins aren’t born, they’re made,
Rich
Contact Rich at [email protected]
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