1/3 of certain journey is covered at the rate of 25kmph,one-fourth at the rate of 30kmph and the rest at 50 kmph.Find the avg speed for the whole journey.	Options:
A) 25.56 kmph
B) 28.675 kmph
C) 33.333 kmph
D) 40.134 kmph
E) 50.254 kmph
Average speed = total distance / total time   L33.333 kmphM = 3, 4 = 12   Average speed = 12 / (1/3*12*1/25 + ¼ * 12*1/30 +5/50)   = 12/ (4/25 + 3/30+ 5/30   = 150*12/54 = 33.333 kmph   33.333 kmph
<result>C</result>
1/3 of certain journey is covered at the rate of 25kmph,one-fourth at the rate of 30kmph and the rest at 50 kmph.Find the avg speed for the whole journey.