Two slits spaced $0\mathrm{.}210$ mmmm apart are placed $0\mathrm{.}680$ mm from a screen and illuminated by coherent light with a wavelength of $660$ nmnm $.$ The intensity at the center of the central maximum $($$=0)($$=0)$ is I$0$I$0.$ What is the distance on the screen from the center of the central maximum to the first minimum? What is the distance on the screen from the center of the central maximum to the point where the intensity has fallen to I$0/2?$