The inner circumference of a circular race track, 14 m wide, is 440 m. Find radius of the outer circle?
Choose one: A) 22 B) 37 C) 87 D) 84 E) 82

Rationale: "let inner radius be r metres . then , 2 r = 440 ; r = = 70 m . radius of outer circle = ( 70 + 14 ) m = 84 m . answer : d"
Answer: D