B2. In a department store, an escalator runs from the ground floor to the first floor. Dion goes up this escalator; while doing so, he also takes a few steps at a constant pace. Raymond walks on the same escalator, in the opposite direction, from top to bottom, and takes steps at the same pace as Dion. Both take one step per stair. Dion reaches the top after exactly 12 steps; Raymond reaches the bottom after exactly 60 steps.

How many steps would Dion need to reach the top if the escalator were not moving?
B2. 20

Consider three escalators next to each other: the first one goes up, the second one is stationary, and the third one goes down. If Dion takes the first escalator up, he reaches the top after 12 steps. Raymond, who goes up on the third escalator, takes 60 steps to reach the top and is only at $\frac{1}{5}$ of the way after 12 steps. If a third person (let's say Julian) takes the middle escalator (also at the same pace), he is exactly halfway between Dion and Raymond after 12 steps: at $\left(\frac{5}{5}+\frac{1}{5}\right) / 2=\frac{3}{5}$ of the escalator. Therefore, he needs $\frac{5}{3} \cdot 12=20$ steps to reach the top.