Think about it this way: how far do you actually move down? In either case you are going the same distance, so the two cases will equal each other (and they will be calculated the same way). You just need to figure out how they are calculated.
There are two components to the distance you are travelling. The first component is the movement of the escelator itself. This is a simple "distance equals rate times time" expression, where the rate is unknown (you do know how long it takes). The second component is the movement of you stepping down the escelator. Add these two components together and you have the distance you've travelled.
Since there is a variable involved, you need to set the first case equal to the second and solve for the rate at which the escelator is travelling. You can then use that rate to figure out how far you've actually travelled.
Hope this helps. Think about it and give it a try. Let me know if you need more help. Hint: the escelator is 46 steps tall.