A 33-mm wide diffraction grating produces a deviation 33.0° in the second order principal maxima. The wavelength of light is 606 nm. What is the total number of slits on the grating?
Hint: $\sin(\theta) = \frac{m\lambda}{d}$, ($m = 0, 1, 2, ...$) (diffraction grating, principal maxima)
m: the order of the pattern, d: width of each slit, and $\lambda$: the wavelength of the light.
1 nm = $10^{-9}$ m and 1 mm = $10^{-3}$ m.