500
Erick has a big gulp from the 7-11 that has 20 ounces and he drinks 3 ounces per minute. Lesly has a regular 16 ounce iccee and drinks hers at rate of 2 ounces per minute. Write an equation to show when Erick and Lesly's drink will be empty at the same time.
20 - 3x = 16 - 2x