20 inches to 2 feet hint you have to convert them into the same units for reasonable comparison, how do i do that

Yoku is putting on sunscreen. he uses 2\text{ ml}2 ml to cover 50\text{ cm}^250 cm 2 of his skin. he wants to know how many milliliters of sunscreen (c)(c) he needs to cover 325\text{ cm}^2325 cm 2 of his skin. how many milliliters of sunscreen does yoku need to cover 325 \text{ cm}^2325 cm 2 of his skin?

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

For what value of (y) is 3^3/3^y =1/9