Which number should replace both the asterisks in (* /20) x (*/80) = 1 ?
Choose the correct choice from the following answers:
A) 20	B) 40	C) 60	D) 80	E) 120

Rationale: "let ( y / 20 ) x ( y / 80 ) = 1 y ^ 2 = 20 x 80 = 20 x 20 x 4 y = ( 20 x 2 ) = 40 the answer is b ."
Answer: B