The bus that travels from St. Louis to Chicago and back comes to St. Louis every 5 hours while the bus that travels from St. Louis to Springfield and back comes to St. Louis every 4 hours. If at 2:00 o'clock both bused arrived at St. Louis, at what time will they meet in St. Louis again?  Options:
A) 16:00.
B) 18:00.
C) 20:00.
D) 22:00.
E) 24:00.
Time taken by bus to travel from St. Louis to Chicago and back comes to St. Louis = 5 hours   Time taken by bus to travel from St. Louis to Springfield and back comes to St. Louis = 4 hours   Time taken by both buses to meet again in St. Louis will be LCM of 5 and 4 = 20   If the buses start at 2:00 o'clock from St. Louis , they will meet again in St. Louis at 22:00 hours   Answer 22:00.
<result>D</result>
The bus that travels from St. Louis to Chicago and back comes to St. Louis every 5 hours while the bus that travels from St. Louis to Springfield and back comes to St. Louis every 4 hours. If at 2:00 o'clock both bused arrived at St. Louis, at what time will they meet in St. Louis again?