Question

At the start of a birthday party,there are 3 times more boys than girls. After 4 boys and 4 girls left the party,there were 4 times more boys than girls. How many boys were there at the start of the party

Answer 1

`36\ boys`

Explanation:

Let

x------> number of boys at the start of the party

y-----> number of girls at the start of the party

we know that

`x=3y` ------> equation A

`(x-4)=4(y-4)` -----> equation B

substitute equation A in equation B and solve for y

`(3y-4)=4(y-4)`

`3y-4=4y-16`

`4y-3y=16-4`

`y=12\ girls`

Find the value of x

`x=3y` ------>
`x=3(12)=36\ boys`