Weighted Average

[Abdulla]

OA is C

[adam15]

the answer is C.
Would you please tell me where you bought this GMAT practice.

[mehravikas]

Answer should be C - Here's why https://www.beatthegmat.com/weighted-average-t28451.html

[mehravikas]

Whats the source?

OA is C

[Stuart@KaplanGMAT]

Here's another thread in which I discuss using a number line to understand weighted averages:

https://www.beatthegmat.com/what-fractio ... 11500.html

[adamsmith2009]

Just want to confirm that the answer is 66% based on the weighted average method. 1 and 2 are not sufficient so if we combine:

G-----------------Avg----------------U
40 20

U/G = 40/20 = 4/2 = 4/6 or 66%

[Stuart@KaplanGMAT]

Just want to confirm that the answer is 66% based on the weighted average method. 1 and 2 are not sufficient so if we combine:

G-----------------Avg----------------U
40 20

U/G = 40/20 = 4/2 = 4/6 or 66%

No, that's backwards.

The overall average is closer to the undergraduates, so the undergrads must carry more weight.

Well, it may be right if you're answering the wrong question

You've set up the number line and equations properly, but the question is what percent are graduate students, so the answer is 1/3, not 2/3.

[adamsmith2009]

Ahh - I see. I had the undergraduate ratio and not the graduate. Thanks Stuart.