Problem Solving

boomgoesthegmat wrote:A store reported total sales of $385 million for February of this year. If the total sales for the same month last year was $320 million, approximately what was the percent increase in sales?

A) 2%
B) 17%
C) 20%
D) 65%
E) 83%

Percent increase = 100(new - old)/old
So: Percent increase = 100(385 - 320)/(320)
= 100(65)/320
= 6500/320
= 650/32
≈ 20%
Answer: C

RELATED VIDEO
- Percent increases and decreases: https://www.gmatprepnow.com/module/gmat ... video/1078

Cheers,
Brent

boomgoesthegmat wrote:A store reported total sales of $385 million for February of this year. If the total sales for the same month last year was $320 million, approximately what was the percent increase in sales?

A) 2%
B) 17%
C) 20%
D) 65%
E) 83%

We can solve this problem by using the percent change formula:

(New Value - Old Value)/Old Value x 100

We are given:

February sales this year = 385 million = new

February sales last year = 320 million = old


Percent change = (New Value - Old Value)/Old Value x 100

Percent change = [(385 - 320)/320] x 100

Percent change = 65/320 x 100

Percent change = 13/64 x 100 ≈ 13/65 x 100 = 1/5 x 100 = 20%

Answer: B

Hi All,

We're told that a store reported total sales of $385 million for February of this year and the total sales for the same month last year was $320 million. We're asked for the approximate percent increase in sales. This question can be solved in a couple of different ways, including with a mix of 'brute force' and TESTing THE ANSWERS.

Since the 5 answers are specific percentages, one of them must be the approximate percent increase. A couple of them are relative easy to TEST.

1% of $320 million = $3.2 million so....
2% of $320 million = $6.4 million
The difference between $385 million and $320 million is $65 million though, so $6.4 million is about 1/10 of what we need it to be. This points us to the correct answer though....

10% of $320 million = $32 million so....
20% of $320 million = $64 million
That $64 million is almost exactly what we're looking for. The exact percentage would obviously be a little bit MORE than 20%, but Answer C is the only one that's 'close', so this must be the answer.

Final Answer: C

GMAT assassins aren't born, they're made,
Rich