Mrs smith fifth grade class 1/3 were missing in mrs jacobs class 2/5 were missing

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?

Let f(x) = 5/x and g(x)=2x2+5x. what two numbers are not in the domain of f o g