Two cyclists start from the same point in the same direction at 22.5 km/h and 18 km/h. After how many minutes will they be 6 km apart?

Explanation

1. 01

   Same direction: the gap grows at $22.5 - 18 = 4.5$ km/h.

2. 02

   Time $= \frac{6}{4.5} = \frac{4}{3}$ h.

3. 03

   $\frac{4}{3} \times 60 = 80$ min.