The computer school enrolment shows that there are 5 girls in every 12 boys. If the school enrolment in one year is 5,200, how many girls and boys are there?
if there are 5x girls and 12x boys, then
17x = 5200
Hmmm. 17 does not divide 5200.
Now, if there were 5100 students, then x = 300.