In a 600 m race, the ratio of the speeds of two contestants A and B is 5 : 4. A has a start of 100 m. Then, A wins by:	Choose the correct choice from the following options:
A) 200 m B) 20 m C) 403 m D) 20 m E) 23 m

Rationale: to reach the winning post a will have to cover a distance of ( 600 - 100 ) m , i . e . , 500 m . while a covers 5 m , b covers 4 m . while a covers 500 m , b covers 4 x 500 / 5 m = 400 m . thus , when a reaches the winning post , b covers 400 m and therefore remains 200 m behind . a wins by 200 m . answer : a
Answer: A