What is the volume of this rectangular prism 7/5cm 5cm 7/2cm? plz help asap

3382-299=3383- ? fill in the blank?

Mozart lenses inc. recently introduced seelites, a thinner lens for eyelasses. of a sample of 800 eyeglass wearers, 246 said they would purchases their next pair of eyeglasses with the new lenses. lenses inc. estimates that the number of people who purchase eyeglasses in a year is 1,700,000. most eyeglasses wearer buy one new pair of eyeglasses a year. what is the annual sales potential for the new lenses.

What is the area of the triangle 10 13 12