Question

89 children were at a party. When 50% of the girls and 20% of the boys left, there were 55 children remaining at the party. How many boys were at the party at first?​

Answer 1

Explanation:

x: boy

y: girl

x+y=89 & 89-(0.2x+0.5y)=55

⇒x+y=89 & 0.2x+0.5y=34

⇒ x=35 & y=54