In a 500 m race, the ratio of the speeds of two contestants A and B is 3 : 4. A has a start of 200 m. Then, A wins by: Choose the correct choice from the following answers
A) 60 m	B) 100 m	C) 43 m	D) 20 m	E) 23 m

Rationale: "to reach the winning post a will have to cover a distance of ( 500 - 200 ) m , i . e . , 300 m . while a covers 3 m , b covers 4 m . while a covers 300 m , b covers 4 x 300 / 3 m = 400 m . thus , when a reaches the winning post , b covers 400 m and therefore remains 100 m behind . a wins by 100 m . answer : b"
Answer: B