A person covered one-fourth of the total distance at 20 kmph and remaining distance at 24 kmph. What is the average speed for the total distance?	Select
A) 21 (6/7)kmph  B) 22 (6/7)kmph  C) 21 (7/3)kmph  D) 27 (6/7)kmph  E) 21 (1/8)kmph
Let the total distance be x km   total time taken = (x/4)/20 + (3x/4)/24 = x/80 + x/32 = 7x/160   Average speed = x/(7x/160) = 160/7kmph   = 22 (6/7)kmph.   Answer:22 (6/7)kmph
<result>B</result>
A person covered one-fourth of the total distance at 20 kmph and remaining distance at 24 kmph. What is the average speed for the total distance?