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

Answer:

$36\ boys$

Step-by-step 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

$x=3y$  ------> $x=3(12)=36\ boys$