Question

there are 77 students in the student council. the ratio of girls to boys is 7:4 how many girls are in the student council

Answer 1

`7x-number\ of\ girls\\4x-number\ of\ boys\\\\7x+4x=77\\11x=77\ \ \ \ \ \ |:11\\x=7\\\\7\cdot7=49\\\\There\ are\ 49\ girls`

Answer 2

x - the number of girls
y - the number of boys


`x:y=7:4 \\ (x)/(y)=(7)/(4) \\ 7y=4x \\ y=(4)/(7)x`

The total number of students is 77.

`x+y=77 \\ x+(4)/(7)x=77 \\ (7)/(7)x+(4)/(7)x=77 \\ (11)/(7)x=77 \\ x=77 * (7)/(11) \\ x=7 * 7 \\ x=49`

There are 49 girls in the student council.