How do you turn a decimal into a fraction

The radius of the base of a cylinder is 10 centimeters, and its height is 20 centimeters. a cone is used to fill the cylinder with water. the radius of the cone's base is 5 centimeters, and its height is 10 centimeters.

There is an entrance to the computer room at point e which lies on ab and is 5 feet from point a. plot point e on the coordinate plane. find the distance from the entrance at point e to the printer at point e

When i'm with my factor 5, my prodect is 20 .when i'm with my addend 6' my sum is 10.what number am i