Difficult Math Question #43 - Sets

A ?

800guy wrote:A group of people participate in some curriculums, 20 of them practice Yoga, 10 study cooking, 12 study weaving, 3 of them study cooking only, 4 of them study both the cooking and yoga, 2 of them participate all curriculums. How many people study both cooking and weaving?

A.1 B.2 C.3 D.4 E.5

The best way to do this is to draw a Venn Diagram
Let me know if you need help on that. A search on the topic would certainly help.

Check out
https://www.beatthegmat.com/viewtopic.ph ... nn+diagram


Answer is E anyway

Answer is A.

CnW = 10 - (CnY) - (CnYnW) - only C = 10 - 4 - 2 - 3 = 1

here's the OA:

We know there are 10 people who do cooking as an activity.

3 -> people who do only cooking
4 -> do cooking and Yoga
2 -> do all of the activities
x -> number of people doing cooking and weaving

When you sum all this up, we should have 10. So 3+4+2+x=10 --> x=10-9=1

rajs.kumar wrote:Answer is A.

CnW = 10 - (CnY) - (CnYnW) - only C = 10 - 4 - 2 - 3 = 1

Rajs - your approach is correct, however CnY = 2 (not 4) -- since you need the count for Cny only, you need to subtract 2 that is included as CnYnW

Correct answer is 3

shahmau wrote:

rajs.kumar wrote:Answer is A.

CnW = 10 - (CnY) - (CnYnW) - only C = 10 - 4 - 2 - 3 = 1

Rajs - your approach is correct, however CnY = 2 (not 4) -- since you need the count for Cny only, you need to subtract 2 that is included as CnYnW

Correct answer is 3

I assumed this "4 of them study both the cooking and yoga" to mean only cooking and yoga. If that is not the case I am wrong.

Can anyone explain the approach.

According to me the answer has to be >= 2(Ppl doing all 3 activities).

As far as my approach goes,
Since you have to find n(CnW)

n(Only C) = n(C) - n(CnY) - n(CnW) + n(CnWnY)

3 = 10 - 4 - n(CnW) + 2.

n(CnW) = 5.

Can anyone tell me where am i going wrong?

Regards,
Ali.

Aalriy wrote:Can anyone explain the approach.

According to me the answer has to be >= 2(Ppl doing all 3 activities).

As far as my approach goes,
Since you have to find n(CnW)

n(Only C) = n(C) - n(CnY) - n(CnW) + n(CnWnY)

3 = 10 - 4 - n(CnW) + 2.

n(CnW) = 5.

Can anyone tell me where am i going wrong?

Regards,
Ali.

You are absolutely right, nothing wrong in there IMO