Last year, for every 100 million vehicles that traveled on a certain highway, 40 vehicles were involved in accidents. If 2 billion vehicles traveled on the highway last year, how many of those vehicles were involved in accidents? (1 billion = 1,000,000,000) Select the correct option:
A) 800 B) 900 C) 100 D) 1000 E) 950

Rationale: "to solve we will set up a proportion . we know that “ 100 million vehicles is to 40 accidents as 2 billion vehicles is to x accidents ” . to express everything in terms of “ millions ” , we can use 2,000 million rather than 2 billion . creating a proportion we have : 100 / 40 = 2,000 / x cross multiplying gives us : 100 x = 2,000 * 40 x = 20 * 40 = 800 answer : a"
Answer: A