Solved by picking a smart number:
Let R be the rate, D the distance, and T the time.
We want to know the average R, which is calculated as follows: \(\frac{Total D}{Total T}\).
1. Let us pick a smart number for the total D. D=120. Thus, every third of the total D = 40.
2. Let us now find the time travelled for every third of the total D:\(\frac{40}{80}\), \(\frac{40}{24}\), and \(\frac{40}{48}\), which reduces to \(\frac{1}{2}\),\(\frac{5}{3}\), and \(\frac{5}{6}\).
3. In order to get total T, we have to sum the individual Ts for the 3 thirds up: \(\frac{3}{6}+\frac{10}{6}+\frac{5}{6}=\frac{18}{6}=3\). Hence the total T = 3 hrs.
4. Now we have all the required components, total D and total T, to compute our
average R: \(\frac{120}{3}=40\). Please hit Kudos if you liked this approach