<p>hey, today's question of the day really tripped me up. I know it is only a medium but for some reason i cannot understand the question/answer. </p>
<p>At Central High School, the math club has 15 members and the chess club has 12 members. If a total of 13 students belong to only one of the two clubs, how many students belong to both clubs?</p>
<p>yea i had a problem with this one at first as well..</p>
<p>after i read the collegeboard explanation method i understood it however..is their method for this question the best way to do the problem?</p>
<p>There are 15 Math students: M is 15
There are 12 Chess students: C is 12
Since only 13 are in one or the other, there is overlapping: which is X</p>
<p>15+12-2X=13
X=7
why 2X? because you have to subtract from Math and chess</p>