A wavelength of 625 nm is used in a Young's double-slit experiment. The separation between the slits is d = 1.3 10-5 m. The total width of the screen is 0.20 m. In one version of the setup, the separation between the double slit and the screen is LA = 0.35 m, whereas in another version it is LB = 0.60 m. On one side of the central bright fringe, how many bright fringes lie on the screen in the two versions of the setup? Do not include the central bright fringe in your counting. Verify that your answers are consistent with your answers to the Concept Questions.

bright fringes on one side (version A)

bright fringes on one side (version B)

2 answers

I think it is asking you for n when x is .20 on each screen.
6 bright fringes