A trained covered x km at 90 kmph and another 2x km at 20 kmph. Find the average speed of the train in covering the entire 3x km. Choose the correct choice:
A) 22
B) 99
C) 27
D) 66
E) 887
Total time taken = x/90 + 2x/20 hours   = x/9 hours   Average speed = 3x/(x/9) = 27 kmph   Answer: 27
<result>C</result>
A trained covered x km at 90 kmph and another 2x km at 20 kmph. Find the average speed of the train in covering the entire 3x km.