The jogging track in a sports complex is 1000 meters in circumference. Deepak and his wife start from the same point and walk in opposite directions at 20 km/hr and 15 km/hr respectively. They will meet for the first time in? Select.
A) 50 min  B) 40 min  C) 35 min  D) 25 min  E) 20 min

Rationale: "clearly , the two will meet when they are 1000 m apart to be 20 + 15 = 35 km apart , they take 1 hour to be 1000 m apart , they take 35 * 1000 / 1000 = 35 min . answer is c"
Answer: C