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## Comment on

Population Increase## Hi Brent! In this question, I

https://gre.myprepclub.com/forum/kathleen-s-weekly-salary-was-increased-by-8-percent-to-13649.html#p33761

## Question link: https:/

Question link: https://gre.myprepclub.com/forum/kathleen-s-weekly-salary-was-increased-...

The question (with $237.60) is from the 2nd edition of the GRE Official Guide.

When the test-makers published the 3rd edition, they changed $237.60 to $712.80

I'm not sure why they did that.

The solution is the same, except we divide $712.80 by 1.08 to get an answer of $660

Cheers,

Brent

## Hi Brent, I did it

## Your solution is perfectly

Your solution is perfectly valid. However, just to be clear about the terms, we can't say there was a 325% INCREASE, since it was actually a 225% increase.

However, we CAN say that the 2008 population was 3.25 TIMES the 2007 population.

Then, to find the 2009 population, we just MULTIPLY the 2008 population by 3.25

Cheers,

Brent

## Why did we add one in the new

## Here are a few similar

Here are a few similar examples:

If x is increased by 10%, then the NEW value = x + (10% of x)

= x + 0.1x

= 1.1x

If x is increased by 50%, then the NEW value = x + (50% of x)

= x + 0.5x

= 1.5x

If x is increased by 90%, then the NEW value = x + (90% of x)

= x + 0.9x

= 1.9x

If x is increased by 100%, then the NEW value = x + (100% of x)

= x + x

= 2x

Likewise, if x is increased by 225%, then the NEW value = x + (225% of x)

= x + 2.25x

= 3.25x

Does that help?

Cheers,

Brent

## Hi Brent! I also completed

1. (65,008-19,984)/65,008 * 100 = about 69%

2. Then, I plugged in each answer choice to see which matches/is close to 69%

3. For ex: (210,000-65,008)/210,000 * 100 = 67%, so I went with choice D.

Is my technique applicable for these types of questions or was this a coincidence?

Thanks!

## You got a little lucky on

You got a little lucky on that question, because you calculated the percent increase incorrectly. However, you also tested the answer choices incorrectly, which allowed you to arrive at the correct answer :-)

In your solution, you are saying that percent increase = (100)(new - old)/NEW

The actual formula is as follows:

Percent increase = (100)(new - old)/OLD

So, as a percent increase = (65,008-19,984)/19,984 * 100

≈ 225%