A person travels at a speed of 10 mph from one city to another. However while returning as there was not much traffic. He came with a speed of 15mph. what is his average speed?	Choose the correct choice from the following options.
A) 10Kmph
B) 11Kmph
C) 12Kmph
D) 13Kmph
E) 14Kmph
Average speed = 2xy/(x+y) = (2*15*10)/25= 
<gadget id="calculator">(2*15*10)/25</gadget>
<output>12</output>
12Kmph   ANSWER:12Kmph
<result>C</result>
A person travels at a speed of 10 mph from one city to another. However while returning as there was not much traffic. He came with a speed of 15mph. what is his average speed?