In a 200 m race,A covers the distance in 45 seconds and B in 60 second.In this race A beats B by :  Choose the correct answer:
A) 20 m	B) 50 m	C) 45 m	D) 60 m	E) none of these

Rationale: "solution distance covered by b in 15 sec . = ( 200 / 60 x 15 ) m = 50 m . ∴ a beats b by 50 metres . answer b"
Answer: B