Find the greatest number which leaves the same remainder when it divides 20, 40 and 90. Choose one:	A) 18	B) 8	C) 12	D) 10	E) none of these

Rationale: "90 - 40 = 50 40 - 20 = 20 90 - 20 = 70 the h . c . f of 20 , 50 and 70 is 10 . answer : d"
Answer: D