1. The problem statement, all variables and given/known data 8 bright fringes are counted across 1.06 cm in the air wedge. 2. Relevant equations Δx = L (λ/2t) 3. The attempt at a solution i don't understand whether Δx is: 8Δx = 1.06cm or 7Δx = 1.06cm it said 8 bright fringes but Δx = the distance between dark fringes which one is the correct one? * if you were draw a diagram of the single interference pattern ex. 3 dark fringes is it: bright | dark | bright | dark | bright | dark | bright if this is correct, does it mean # of bright fringes are always 1 greater than the dark fringes?