Cuanto vale 2i por favor

Asphere has a diameter of 10 in. what is the volume of the sphere?

Which expression gives you the distance between the points (5,1)and(9,-6)

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.