# Cheryl climbed a set of stairs and stopped at the middle step. She then walked down 2 steps, up 4 steps, down 3 steps, and up 5 steps, and she was at the top of the stairs. How many steps are in the set of stairs?

##### 1 Answer

Jun 9, 2017

#### Answer:

#### Explanation:

We know that Cheryl was at the middle of the set of stairs. Let the middle step be

Since she walked down 2 steps, that can be modelled as

We continue modelling it, until we get

Therefore, from the middle of the set of stairs to the top, there are 4 steps. That means that since

Therefore, including the middle step, we have