In a double slit experiment, light waves pass through two narrow slits that are spaced a distance $d$ apart. The interference pattern is observed on a screen that is a distance $L$ from the slits.

An interference pattern is shown on the right. The small divisions on the scale on the right represent mm. The wavelength of the light used in the experiment is $\lambda=$ nm. The distance to the screen $L=1$ m. What is the distance $d$ between the slits?