Two persons start running simultaneously around a circular track of length 400 m from the same point at speeds of 20 km/hr and 30 km/hr. When will they meet for the first time any where on the track if they are moving in opposite directions?	Choose one:
A) 28 sec B) 37 sec C) 21.6 sec D) 23 sec E) 27 sec
Time taken to meet for the first time anywhere on the track   = length of the track / relative speed   = 400 / (20 + 30)5/18 = 300* 18 / 50 * 5 = 21.6 seconds.   Answer : 21.6 sec
<result>C</result>
Two persons start running simultaneously around a circular track of length 400 m from the same point at speeds of 20 km/hr and 30 km/hr. When will they meet for the first time any where on the track if they are moving in opposite directions?