Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph, he will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M.?  Options.
A) 9 km/hour
B) 10 km/hour
C) 11 km/hour
D) 12 km/hour
E) 13 km/hour
Explanation:   We need to calculate the distance, then we can calculate the time and finally our answer.   Lets solve this,   Let the distance travelled by x km   Time = Distance/Speed   x/10−x/15=2   [because, 2 pm - 12 noon = 2 hours]   3x−2x=60x=60.   Time=Distance/Speed   Time@10km/hr=60/10= 
<gadget id="calculator">60/10</gadget>
<output>6</output>
6hours   So 2 P.M. - 6= 8 A.M   Robert starts at 8 A.M.   He have to reach at 1 P.M. i.e, in 5 hours   So, Speed = 60/5= 
<gadget id="calculator">60/5</gadget>
<output>12</output>
12 km/hr   Option 12 km/hour
<result>D</result>
Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph, he will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M.?