Yes because,
8×1 = 8
8×2 = 16
8×3 = 24
8×4 = 32
8×5 = 40
So 40 is a multiple of 8
Answer: Increase in number or size, at a constantly growing rate. It is one possible result of a reinforcing feedback loop that makes a population or system grow (escalate) by increasingly higher amounts.
I got 130.24 square feet. Hope that helps.