SOLUTION: Every student in a school studies either mathematics or physics. Two-thirds of the students study mathematics and one-half of the students study physics. If seven students study bo

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Every student in a school studies either mathematics or physics. Two-thirds of the students study mathematics and one-half of the students study physics. If seven students study bo      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 206859: Every student in a school studies either mathematics or physics. Two-thirds of the students study mathematics and one-half of the students study physics. If seven students study both subjects, what is the total number of students in the school?
(A) 42 (B) 49 (C) 84 (D) 98 (E) None of these
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
2x/3+x/2-7=x
(2*2x+3*x)/(2*3)-7=x
(4x+3x)/6-7=x
7x/6-7=x
7x/6-x=7
7x/6-6x/6=7
x/6=7
x=7*6
x=42 is the total number of students.
Proof:
2*42/3+42/2-7=42
84/3+21-7=42
28+21-7=42
42=42