In the experiment to measure the wavelength of a monochromatic light beam, the beam is directed at two slit Young apart

= 0,07 mm. Adjust the viewing screen position to the position two slits
a segment D = 1.5 m then the background interference on the screen.
a) The measured 5th order dark fringe position is y = 4.5 cm. Calculate the wavelength  of the light beam.
b) Calculate the distance from the 3rd order bright fringe to the 5th order dark fringe.
c) Calculate the number of bright fringes observed on the screen.