1. The problem statement, all variables and given/known data Monochromatic light passes through 2 narrow slits 0.25mm apart and forms an interference pattern on screen 1.5m away.If light with a wavelength of 680nm is used,what is the distance between center of central maximum and center of the third-order bright fringes? 2. Relevant equations sorry don't have.. 3. The attempt at a solution d=0.25mm ,y=1.5m lambda=680x10^-9, central max=0, third order=3 i tried using sin@=m x lambda /d ,but y is given..i think i should have use it but then i don't know where n when to use..can you please hint me?