Question 53534
<pre><font size = 5><b>At Annville high school,30% of the students in
the Math club are in the Science club, & 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?

Let M = number of students in the math club.

Number of students in the math club that are
also in the science club = 30% of M = .3M

Number of students in the science club that
are also in the math club = 80% of 15 or 12
 
These are equal

.3M = 12
  M = 12/.3
  M = 40

So there are 40 students in the math club.

Edwin</pre></font><b>