80 370 ? 1550 2440 3530
Pick
A) 900	B) 840	C) 750	D) 860	E) 960
10^2 - 20 = 80   20^2 - 30 = 370   30^2 - 40 = 860   40^2 - 50 = 1550   50^2 - 60 = 2440   60^2 - 70 = 3530.   ANSWER:860
<result>D</result>
80 370 ? 1550 2440 3530