A person covered one-fourth of the total distance at 6 kmph and remaining distance at 24 kmph. What is the average speed for the total distance?  Choices.
A) 10(5/7)kmph  B) 21(2/3) kmph  C) 13 (5/7)kmph  D) 15 (5/7)kmph  E) 13 (2/7)kmph
Let the total distance be x km   total time taken = (x/4)/6 + (3x/4)/24 = x/24 + x/32 = 7x/96   Average speed = x/(7x/96) = 96/7kmph = 13 (5/7)kmph.   ANSWER:13 (5/7)kmph
<result>C</result>
A person covered one-fourth of the total distance at 6 kmph and remaining distance at 24 kmph. What is the average speed for the total distance?