Two cyclist start from the same places in opposite directions. One is going towards north at 5kmph and the other is going towards south 5kmph. What time will they take to be 50km apart?	Select.
A) 1 hr	B) 2 hrs	C) 3 hrs	D) 5 hrs	E) 6 hrs

Rationale: "to be ( 5 + 5 ) km apart , they take 1 hour to be 50 km apart , they take 1 / 10 * 50 = 5 hrs answer is d"
Answer: D