On monday the escalator was not working. it took tom 18 seconds to reach the top, climbing two steps each second. by tuesday the escalator had been repaired and tom took only 12 seconds to reach the top climbing at the same rate. on wednesday tom decided to ride the escalator without climbing at all. how long did it take to reach the top this time?

*There are 36 steps on the elevator as it took Tom 18 seconds to reach the top of the elevator (when it wasn't working), taking 2 steps per second.(2*18=36).

*When the elevator was fixed Tom moved through it taking 2 steps per second and managed to reach its top in 12 seconds. This means that he had covered 3 steps in the space of a second while he was moving up the elevator (fixed). (36/12=3).

*Knowing this information, we can come to terms with the fact that the elevator can move Tom 1 step upwards per second if he doesn't make any effort to move up the elevator while its working. As there are 36 steps on the elevator, on Wednesday it took Tom 36 seconds to reach its top.

38 dollars is your answer.