two cyclist start from the same places in opposite directions . one is going towards north at 10 kmph and the other is going towards south 10 kmph . what time will they take to be 50 km apart ?
"to be ( 10 + 10 ) km apart , they take 1 hour to be 50 km apart , they take 1 / 20 * 50 = 2.5 hrs answer is b"
divide(50, add(10, 10))