Monochromatic light of a single light source of wavelength 560 nm is passed through two narrow slits B and C. The distance from the central maximum to the first dark band is 1.3 mm. If the perpendicular distance from the slits to the screen is 1.3 m, the distance between B and C is Blank 1. Fill in the blank, read surrounding text. mm. State your answer accurate to 2 decimal places.