Okay last question I need help with

Question

Monochromatic light of 605 nm falls on a single slit, which is located 85 cm from a screen. The first dark band appears at 5.4 mm from the center. How wide is the slit?

0.001 mm

0.050 mm

0.095 mm

1.50 mm

Answer 1

i'm thinking it's c?

Answer 2

1 * 605 * 10^-9 * .85 / 5.4 *10^3

= 95 * 10^-6 m

= .095 mm

Answer 3

Damon, I could hug you. You answer so many of the questions I am looking for. You make it so easy, so thanks for being you!