im not sure how to write the question on here but i put a pic of it down below its a proof question for math 10th grade geometry .

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.

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Joe has some money in his bank account he deposits 45$ write an expression that represents the amount of money in joe's account