A man cycled 25 kilometer in 1 hour 40 minutes. what was the average speed of cylcle in kilometer per hour? Choose the most appropriate option.
A) 7 miles / hour  B) 9 miles / hour  C) 10 miles / hour  D) 13 miles / hour  E) 15 miles / hour
We first convert the time of 1 hours 10 minutes in minutes   1 hours 10 minutes = 1* 60 + 40= 
<gadget id="calculator">1* 60 + 40</gadget>
<output>100</output>
100 minutes   Average speed S is given by distance / time. Hence   S= 25 miles / 100 minutes = 0.25 mile / minute   = 15 miles / hour   correct answer 15 miles / hour
<result>E</result>
A man cycled 25 kilometer in 1 hour 40 minutes. what was the average speed of cylcle in kilometer per hour?