A and B go around a circular track of length 600 m on a cycle at speeds of 36 kmph and 54 kmph. After how much time will they meet for the first time at the starting point? Pick
A) 120 sec  B) 176 sec  C) 178 sec  D) 187 sec  E) 189 sec
Time taken to meet for the first time at the starting point   = LCM { length of the track / speed of A , length of the track / speed of B}   = LCM { 600/ (36 * 5/18) , 600/ (54 * 5 /18) }   = LCM (60, 40) = 120 sec.   120 secnswer: 120 sec
<result>A</result>
A and B go around a circular track of length 600 m on a cycle at speeds of 36 kmph and 54 kmph. After how much time will they meet for the first time at the starting point?