Boys Vs Girls!

Boy and Girl standing in a queue

From a group of boys and girls,15 girls leave. There are then left 2 boys for each girl.After this,45 boys leave.There are then 5 girls for each boy.Find the number of girls in the beginning.

The average weight of girls is 15 and the average weight of boys is 30 and the average weight of boys and girls both is 25. If the number of boys are 12, then the number of girls is :

There are 1550 boys and girls in a school. The number of girls exceeds the number of boys by 500. What is the percentage (to nearest integer) of girls in the school?

There are 1550 boys and girls in a school. The number of girls exceeds the number of boys by 500. What is the percentage (to nearest integer) of girls in the school ?

The ratio of the boys to girls in a class is 2:3 . If 20% of boys leave this class,then the new ratio of boys to girls is