A trained covered x km at 50 kmph and another 2x km at 20 kmph. Find the average speed of the train in covering the entire 3x km.
Answers:
A) 22 B) 99 C) 25 D) 66 E) 887
Total time taken = x/50 + 2x/20 hours   = 6x/50 = 3x/25 hours   Average speed = 3x/(3x/25) = 25kmph   Answer: 253 /(3 /25)= 
<gadget id="calculator">3 /(3 /25)</gadget>
<output>25</output>
25kmph   Answer: 25
<result>C</result>
A trained covered x km at 50 kmph and another 2x km at 20 kmph. Find the average speed of the train in covering the entire 3x km.