<em>Multiply the length, the width, and the height. You can multiply them in any order to get the same different result. The formula for finding the volume of a rectangular prism is the following: Volume = Length * Height * Width, or V = L * H * W.</em>
You would multiply the students by the price (12*10=120) then multiply chaperones by price (6*15=90) then add both prices together to get 210. Then you would subtract 210 from 380 to get how many boys are in the class. 380-210=170. Since each student cost 10 so you would divide 170/10=17. There would be 17 boys in your class.