+866 Annville Junior High School has a math club and a science club. There are $3$ students in the math club and $3$ students who are members of both clubs. There are twice as many students in the science club as in the math club. Find the total number of students who are in the math club or the science club (or both).
+174 There are 3 students in the math club, and 3 are in both clubs, so there are 3−3=0 students in just the math club.
The science club has twice as many students as the math club, so it has 2⋅3=6 students.
If we add the number of students in each club (without double counting the 3 who are in both), we get 0+6=6 students.
However, this double counts the 3 who are in both clubs. So, the total number of students who are in the math club or science club (or both) is 6−3=3 students.
