Adam was walking down the stairs at his work one day. Adam began on the top step and had already gone down seven steps when he saw Reanna on the ground floor beginning to come up the stairs. Reanna goes up two steps for every one step Adam goes down. Adam was shocked to see that when he still had four steps remaining, Reanna had already climbed the entire staircase. How many steps does the staircase have?

please help. if you could help me figure out how to solve it that would be great. thanks (:

A+7-4=R

but R=A/2 think about that.

A+3=A/2

A=6 steps. so the stair case has 6+7+4