Wednesday, May 18, 2016

stretch your brain a bit

Here's an Algebra 1-level question from the SAT—no not that SAT, but the Samsung Aptitude Test, which you can learn more about by reading this article (hat tip to Chelsea on Twitter for the link). It took me about a minute (OK, maybe a bit more) to get the answer.

The number of male employees decreased by 10% compared to the previous year. The number of female employees increased by 15%. There are currently a total of 182 employees at the company. If there were 20 more male employees than female employees last year, how many female employees are at the company this year?

Enjoy. Leave your answer in the comments. Feel free to discuss how you figured it out.


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4 comments:

Joe Walther said...

92.
Why? Because math.

Kevin Kim said...

My own procedure for tackling this problem:

1. Define "this year" and "last year" as 2016 and 2015, respectively.
2. Let #male & female employees in 2015 = m & f, respectively.
3. For 2015, let m = f + 20, i.e., m - f = 20.
4. #male employees in 2016 = 0.9m. (10% fewer than prev. yr.)
5. #female employees in 2016 = 1.15f. (15% more than prev. yr.)
6. Let 0.9m + 1.15f = 182. (current total, 2016)
7. Systems of equations:

0.9m + 1.15f = 182
m - f = 20

8. Multiply bottom equation by 1.15. System now looks like:

0.9m + 1.15f = 182
1.15m - 1.15f = 20

9. Add equations, resulting in:

2.05m = 205

Therefore m = 100 and f = 80 (in 2015, remember)

80 * 1.15 = 92 female employees in 2016.

QED.

Kevin Kim said...

You look really, really serious in that photo, Joe. Sort of an "angry Jeremy Renner-as-sniper" thing going on.

Joe Walther said...

Thanks.
I think.