A person covered one-fourth of the total distance at 18 kmph and remaining distance at 24 kmph. What is the average speed for the total distance?  Choose the correct choice from the following options
A) 21 (1/18)
B) 21 (1/13)
C) 21 (8/13)
D) 22 (2/13)
E) 21 (4/13)
Let the total distance be x km   total time taken = (x/4)/18 + (3x/4)/24 = 13x/288   Average speed = x/(13x/288) = 22 (2/13)kmph.   Answer: 22 (2/13)
<result>D</result>
A person covered one-fourth of the total distance at 18 kmph and remaining distance at 24 kmph. What is the average speed for the total distance?