Question 5
The conditions of the road between Town $A$ and Town $B$ can be classified as up slope, horizontal or down slope, and the total length of each type of road is the same. A cyclist travels from Town $A$ to Town $B$ with uniform speeds $8$ km/h, $12$ km/h and $24$ km/h on the up slope, horizontal and down slope road respectively. What is the average speed of his journey?
