what was the original number of students present?

Question

A classroom contains an equal number of boys and girls. If 8 girls leave, twice as many boys as girls remain. What was the original number of students present?

Answer 1

Vanessa,

 

x = number of boys

y = number of girls

x = y

 

2(y-8) twice as many remaining girls = x the number of boys which is unchanged which, most importantly, is equal to y which is the number of girls before 8 of them left.

 

2(y-8) = y

2y -16 = y

y = 16, => x = 16

The original number of students present is (x+y) 32.