Hi there, would you please solve it real quick, that would be very helpful and appreciated. I will give you a good feedback too. Thank you.

Red laser light of wavelength 633 nm is incident on a diffraction grating. On a screen 1.5 m away the first order bright spots on each side of the central bright spot are 0.46 m apart from each other. How many slits/m are there on the diffraction grating