He earned $325 because 900 divided by 4% = $225! :)
Foil method:
FOIL stands for
first-multiply the first term in each set of parenthesis
outer-multiply the outer term in each of the perenthesis
inner- multiply the inner term in each of the parenthesis
last- multiply the last term in each of the parenthesis
(3x+8)(x+1)
(3x*x)=3x^2
(3x*1)=3x
8*x=8x
8*1=8
thus we shall have:
3x^2+3x+8x+8
=3x^2+11x+8
Distributive property:
(3x+8)(x+1)
3x(x+1)+8(x+1)
3x^2+3x+8x+8
=3x^2+11x+8
Both methods are efficient, it all depends with the users preference
I think you can do this way:
Volume = B*h where B is the area of the base.
B= 4 * 10 = 40
V= 40 * 15
V= 600 cm^3
