A music festival took place over two days, Saturday and Sunday. What

I think, "attendees" implies that at least one of the days was attended by everyone. Hence the case of neither Saturday nor Sunday is 0.

Obviously Statement 1 or 2 alone are not sufficient.

Combining both we can find % of attendees who only attended on Saturday.


Answer C.


Thanks,
GyM

30% on Sunday only. 40% on Saturday and Sunday. Since every person attended at least on one day, 30% attended on Saturday. Hence, answer choice C.

Statement 2 says that 70% attended on Sunday .... This implies that 70% includes those that attended only on Sunday and those who attended both days (since someone who attended both days would have automatically attended on Sunday too, and hence part of the 70%)
Therefore, 100%-70%=30% attended on Saturday.
Therefore B.

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Since it's percentage of attendees, the number who didn't attend on either days is 0.

Statement 1: 40% of attendees attended both days. Insufficient.


Statement 2: 70% of attendees attended on Sunday. Insufficient.

Taken Together,

Out of 100 attendees, 70 attended on Sunday, 40 attended on both days;

This means that number of attendees who attended only on Sunday = 70 - 40 = 30.

Therefore, the number who attended only on Saturday = 100 - 40(Both) - 30(only Sunday) = 30. Sufficient.

Hence, the Answer is C.

Attendees should mean that there is no one outside the group of Saturday and Sunday. S IMO option B should be sufficient.

Dear GMATGuruNY

Can you help with this question? From OA, it is assumed that the festival connected on both days, while the wording, for me at least, may suggest only it is 2 days festival? How can I infer that someone who attended on Sunday must have attended on Saturday?

Bunuel

Can you please post the official answer by Veritas?

A music festival took place over two days, Saturday and Sunday.
This wording conveys that the festival lasted exactly two days (Saturday and Sunday).



The prompt does not indicate that anyone who attended Sunday must also have attended Saturday.
Before we examine the statements, we know only the following:
Anyone who attended the festival must have attended only Saturday, only Sunday, or both days.
Let the total number of attendees = 100.

Statement 1: 40% of attendees attended both days.
No way to determine how many attendees attended only Saturday.
INSUFFICIENT.

Statement 2: 70% of attendees attended on Sunday.
Since 70 of the 100 attendees attended Sunday, the remaining 30 did NOT attend Sunday and thus must have attended only Saturday.
SUFFICIENT.

Event took place on 2 days. So no other day we can consider.

People who have not attended are never called attendees.

Using this information we move forward.

Let X be the people who have attended event only on Saturday.

Let Y be the people who have attended event only on Sunday.

Let Z be the people who have attended event on both Saturday and Sunday.

So,

X+Y+Z = 100% ------- (1)

Statement A - 40% of attendees attended both days.

This means our Z = 40%. ----- (2)

But we still cannot find X using equation (1) & (2)

Hence Statement (A) is insufficient.

-----------------------------

Statement B - 70% of attendees attended on Sunday.

This means our Y + Z = 70% ------- (3)
because Z includes people who have visited on sunday as well and not only saturday

Hence using equation (1) and (3) we can find X.

Hence Statement (B) is sufficient.

-----------------------------

Hence answer then becomes B

Note: Statement 2 does not say "70% of attendees attended ONLY on Sunday."
The question asks for the percent of attendees ONLY on Saturday. Therefore it is simply 100 - 70 = 30%. SUFFICIENT. --> (B)

If the question asked for the percent of attendees on Saturday, you would require both statements.

VeritasKarishma i picked E, cause no info on "neither" is given. how can can i figure our when "neither" is implied 0 VS "neither" is unknown, just in general.

dave13 - The backstory often gives you clues. A music festival took place over 2 days only (Saturday and Sunday). So all attendees would attend on Saturday or/and Sunday. Only then can we call them "attendees".
Can there be an attendee that attended the festival on neither of the two days? No. Then we cannot call him an attendee. Hence, neither = 0.

If the question were in terms of city's population, then we know that there could be people who did not attend the festival. Instead of attendees, we would have population then.
"40% of the city's population attended on both days" and "70% of city's population attended on Sunday."
etc

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