A train sets off at 9:00 am at the speed of 70 km/h. Another train starts at 10:30 am in the same direction at the rate of 80 km/h. At what time will the second train catch the first train?
Choose one:
A) 7:00
B) 8:00
C) 9:00
D) 10:00
E) 11:00
In one hour and thirty minutes the first train travels 105 km.   The second train catches the first train at a rate of 80 km/h - 70 km/h = 10 km/h.   The second train will catch the first train in   105/10= 
<gadget id="calculator">  105/10</gadget>
<output>21/2 = around 10.5</output>
10.5 hours, so at 9:00 pm.   The answer is 9:00.
<result>C</result>
A train sets off at 9:00 am at the speed of 70 km/h. Another train starts at 10:30 am in the same direction at the rate of 80 km/h. At what time will the second train catch the first train?