A boy rides his bicycle 20km at an average speed of 20km/hr and again travels 30km at an average speed of 10km/hr. His average speed for the entire trip is approximately? Choose the correct choice from the following answers: A) 10.6km/hr B) 8.9km/hr C) 15.5km/hr D) 12.5km/hr E) 15km/hr
Total distance traveled = 20+30= 
<gadget id="calculator">20+30</gadget>
<output>50</output>
50km   Total time taken= 20/20 + 30/10= 
<gadget id="calculator">20/20 + 30/10</gadget>
<output>4</output>
4 hrs   Average speed= 50/4= 
<gadget id="calculator">50/4</gadget>
<output>25/2 = around 12.5</output>
12.5km/hr   Answer is 12.5km/hr
<result>D</result>
A boy rides his bicycle 20km at an average speed of 20km/hr and again travels 30km at an average speed of 10km/hr. His average speed for the entire trip is approximately?