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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%