Menti Girls v/s Boys special-evening

The set of girls in a boys school is :

There are two boys and three girls. A committee of two is to be formed. Find the probability that the committee contains (i) Only girls (ii) One boy and one girl Only boys (iv) at least one girl

In a class, there are 10 boys and 8 girls. When 3 students are selected at random, the probability that 2 girls and 1 boy are selected, is

There are 40 children in a playground. If the number of girls is 25 and the remaining are boys, find the ratio of: The number of girls to the number of boys.

The number of ways in which 15 boys and 2 girls can sit in a row such that between the girls at the most 2 boys sit is

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.