Specific Math Problem. Please Help!

<p>Of the 48 students in tenth grade at a certain hgih school, 30 study arty, 25 study music, and 9 study neither. how many students study both art and music?</p>

<p>A)7
B)9
C)11
D)16
E)25</p>

<p>Thank you!</p>

<p>I have no idea how one can do this. How do you set it up? What formula? What do I do.</p>

<p>Thanks!</p>

<p>hrmm. Barron's will explain this. But i forgot and I have school so I'll do my post later tonight when i can look it up in the book.</p>

<p>Just keep thinking and you'll have an insight. </p>

<p>48 - 9 = 39
39 = (30 - x ) + ( 25 - x )
-16 = -2x
x = 8</p>

<p>39 - (30 - 8) - (25-8) = 0</p>

<p>Answer is D =]. MUHAHHAHA. I did it right the first time but I subtracted wrong. So i gues its D because 8 students from the art class and 8 from the music class study both. holla!</p>

<p>Or, without the algebra: Since there are 48 total and 9 that study neither art nor music, there must be 39 that study art, music or both. Since there are 30 that study art, there must be 9 that study music but not art. Since there are 25 that study music, there must be 16 that study both art and music.</p>

<p>you can always just do a quick trial and error...</p>

<p>plug in C for the answer choice and move on... eventually you will find D</p>

<p>30 study art
25 study music
9 do neither</p>

<p>if you plug in 11 then it'd be</p>

<p>11 + (30-11) + (25-11) + 9 = 48</p>

<p>11 --> 53 so it's too high... thus more students... go with 16 now</p>

<p>16 + (30-16) + (25-16) + 9 = 48</p>

<p>16 + 14 + 9 + 9 = 48... 30 + 18 = 48</p>

<p>boom it's 16</p>