How do I solve these equations?

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

Alana has 12.5 cups of flour with which she is baking four loaves of raisin bread and one large pretzel. the pretzel requires 2.5 cups of flour to make. how much flour is in each loaf of raisin bread? explain the steps to follow to get the answer.

Find the greatest common factor of the followig monomials 46g^2h and 34g^6h^6