Two cars start at the same time from opposite ends of a highway that is 333 miles long. One car is riding at 54 mph and the second car is riding at 57 mph. How long after they begin will they meet?
Answers:
A) 1 B) 2 C) 3 D) 4 E) 5

Rationale: "as cars are moving in opposite directions their speeds will be added . so their relative speeds : 57 + 54 = 111 mph total distance to be covered = 333 miles . time taken would be : 333 miles / 111 mph = 3 hours c is the answer ."
Answer: C