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# Can I get some help with this one?

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At Annville Junior High School, 30% of the students in the Math Club are in the Science Club, and 80% of the students in the Science Club are in the Math Club. There are 15 students in the Science Club. How many students are in the Math Club?

Oct 21, 2017

#1
+7348
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There are  15  people in the science club.

80% of the people in the science club are in both the science and math clubs, so...

number of people in both clubs  =  0.8 * 15  =  12

Let the number of people in math club  =  m

30% of the people in the math club are in both the science and math clubs,

and remember there are  12  people that are in both clubs, so...

0.3m  =  12

m  =  12 / 0.3

m  =  40

Oct 21, 2017
#2
+95856
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There are 15 students in the Science Club.......80%  of these are in the Math Club....

Note that 80%  =  4/5....so 4/5 * 15  =  60/ 5 = 12

So....12 students in the Science Club are Math Club members

And these 12 represent 30% of the Math Club

Call the total members in the Math Club, M

So.....

30% of M  = 12      or, put another way

.30 M  = 12        divide both sides by .30

M  =  12 / .30  =  40 students in the Math Club

Oct 21, 2017
#3
+95856
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Sorry, hectictar.....I didn't see that you were answering, too....

Oct 21, 2017
#4
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I went into hiding!!

Well..... I logged out before I started answering because I didn't know for sure if I could get it

hectictar  Oct 21, 2017
#5
+95856
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Oct 21, 2017
#6
+7348
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They'll sneak up right behind you...and suddenly....BOO!!

It  is close to Halloween, after all !!! Gotta watch out!!

Oct 21, 2017
edited by hectictar  Oct 21, 2017