Jagan went to another town covering 240 km by car moving at 60 kmph. Then he covered 400km by train moving at 100 kmph and then rest 200 km he covered by a bus moving at 50 kmph. The average speed during the whole journey was ? Choose the correct answer
A) 80 kmph  B) 60 kmph  C) 10 kmph  D) 70 kmph  E) 90 kmph
Explanation:   By car 240 km at 60 kmph   Time taken = 240/60= 
<gadget id="calculator">240/60</gadget>
<output>4</output>
4 hr.   By train 240 km at 60 kmph   Time taken= 400/100= 
<gadget id="calculator">400/100</gadget>
<output>4</output>
4 hr.   By bus 240 km at 60 kmph   Time taken= 200/50= 
<gadget id="calculator">200/50</gadget>
<output>4</output>
4 hr.   So total time= 4 + 4 + 4= 
<gadget id="calculator">4 + 4 + 4</gadget>
<output>12</output>
12 hr.   and total speed= 240+400+200= 
<gadget id="calculator">240+400+200</gadget>
<output>840</output>
840 km   Average speed of the whole journey= 840/12= 
<gadget id="calculator">840/12</gadget>
<output>70</output>
70 kmph.   Answer: 70 kmph
<result>D</result>
Jagan went to another town covering 240 km by car moving at 60 kmph. Then he covered 400km by train moving at 100 kmph and then rest 200 km he covered by a bus moving at 50 kmph. The average speed during the whole journey was ?