Can you please explain how to solve these problems

Like first and second dark light n values supposed to be different?

I would appreciate it if you can explain the equation too

1) (2 pt) A light wave with wavelength 500 nm encounters a double slit with spacing 0.15 mm. i. The angle from the center at which the first bright band (not counting zero) will appear is A. 0.05* B. 0.10 C. 0.19 D. 0.29 E. 0.38 ii. The second bright band will occur A. At double this angle B. At triple this angle C. At quadruple this angle D. At ten times this angle E. Never. There will only be one dark band. 2) (2 pts) Light travels from material A, which has index of refraction 1.25, through a thin film of material B, which has index of refraction 1.10. The film is on top of material C, which has index of refraction 1.50. The thin film is 100 nm thick. We seek a color of light (which has wavelength A in vacuum) that will be removed from the reflected light. An appropriate interference condition is 200 nm =_ iii. First blank: A. 0.5 B. 1 iv. Second blank: A. A B. X/1.10 C. X/1.25 D. X/1.50