GMAT Diagnostic Test Question 22

To me this seems to be a 650 problem, and not 750.

i gotta agree, this seemed a little bit easier than a 750 might be. i'd think its a 650. MAYBE a 700. but then again, what would i know. i haven't taken the test yet and won't for about 3 more months.

Thank you. This feedback helps!

i tend to like to plug in numbers when possible so i approached this question as saying

100 people visited the zoo.

40 families (40% of 100)
10 with multiple children (25% of 40)
Therefore 30 with single children (40-10)

30/100 = 30%.

rated it low because this is below even a 650 question in my opinion. Still love the diagnostic test though!

totally agree. This one is a bit easy.

This looks like it can be a 650 question at max. More likely a 600 question. Thanks for the awesome test!

This is a badly-worded question.



1) It assumes that single visitors do not have children. This is certainly not a reflection of real life, so how are we supposed to know this when we first read the question?

2) There's no such thing as a "family visitor" in the English language. If you're going to distinguish this from "single", then maybe use "married". Otherwise, it's impossible for the reader to know that to "single" and "family" are mutually disjoint sets.

Here's what I would write:

60% of the San Diego Zoo visitors are single without children, and the rest are married with children. If 25% of the married visitors have multiple children, what percentage of the San Diego Zoo visitors have only one child?

Thanks, I we will correct that. +1.

I think its easier if you think of it like this.

60% are single w/o children which equals 40% are married w/ children (1-.6)
25% of the 40% have multiple children. So 25% of 40% is 10% (.25*.4 = .1 or 10%)

So just subtract married w/ children(40%) from married visitors w/o multiple children (10%) and you get married with 1 child
40% - 10% (.4-.1) = 30%

I have to agree with AloneAndInsufficient, who mentioned the poor wording of the question. I got tripped up because apparently the question is including everybody in a family as one visitor.

"60% of the San Diego Zoo visitors are single and all of the San Diego Zoo family visitors have children. If 25% of families visiting the San Diego Zoo have multiple children, what percentage of the San Diego Zoo visitors have only one child?"

75 percent of families have one child. But the question, instead of counting two parents and a child as three people, it counts them as one. I was confused by that, because I thought 10 families with a child each would count as 30 people, rather than 10 visitors.

Maybe I'm the only one tripped up by that. But it's either something to correct in the diagnostic, or a good lesson to us newbies that the GMAT can sometimes use ambiguous wording and not to dig too deeply into the question.

It cannot be a 750 level question...

Easy one take x=100 and now solve.

will get the answer as 30.

This question is too easy to be 700+.

Lets assume that 100 is our total number of visitors to the zoo.
so, .6*100 will give us 60, so 100-60 will give us 40 married visitors with children.
so, if we take .25 * 40 will give us 10; therefore, we can 40-10 will give us = 30.
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Answer. C