Question

A classroom contains an equal number of boys and girls. If 11 girls leave, twice as many boys as girls remain. What was the original number of students present?

Answer 1

44 students

Explanation:

Let

x ---> original number of boys

y ----> original number of girls

we know that

Originally

`x=y` ----> equation A

If 11 girls leave, twice as many boys as girls remain

so

`x=2(y-11)` ----> equation B

substitute equation A in equation B

`x=2(x-11)`

solve for x

`x=2x-22\\2x-x=22\\x=22\ boys`

Find the value of y

y=x

so

`y=22\ girls`

The original number of students present is equal to

`x+y=22+22=44\ students`