M01-15

I think the answer should be E. The question does not say that ALL swim team members are included in the 40%, but rather that 40% of all students are members of both. If we assume that there are 100 total students, there could be 40 members of the swim team, or 100 members of the swim team. All we know is that 40% of these students are members of both.

I set up a table:

Chess
Yes No Total
Swim Yes .40x .20x .60x
No n/a n/a .40x
Total 1.0x


Sorry if the above table is garbled, but I hope it presents properly. If you add all the members of the swim team (40% who are both Swim and Chess and 20% who are not on the Chess team) then you get 60%.

Hi Bunuel

I have a doubt about your explanation. Requesting you to please help.

out of 100 total students, there can be the case that a student is neither a part of chess club nor a part of swim team. How you have managed this case in your explanation? Please explain.

Thank You.

There certainly can be students who are neither in a chess club nor in a swim team but to solve the question we don't need to know how many. In this post there is a matrix that might help.

Thank you so much, Bunuel. Got it.

I think this is a high-quality question and I agree with explanation.

I have edited the question and the solution by adding more details to enhance its clarity. I hope it is now easier to understand.

I like the solution - it’s helpful.

I like the solution - it’s helpful.

I like the solution - it’s helpful.

I like the solution - it’s helpful.