So I Know Nothing About Math And I Need To Get This Done. Here Is The Problem

I Have A Footprint Of A House. And There Are 7 Options That Could Change That Footprint. So How Many Footprints Can There Be Total?

1 Footprint

7 Options

You Cannot Use The Same Option. So If I Used Option A And Added Option B, When It Comes To Figure Out The Options On B I Cant Use A. Make Sense? I Think The Answer Is 148 But Im Not Sure. Please Help Anyone.