Final answer:
The ratio of the width of the slits to the separation between them can be found using the interference and diffraction equations.
Step-by-step explanation:
To find the ratio of the width of the slits to the separation between them, we need to consider the interference pattern produced by the double slit. The first minimum of the single-slit pattern falls on the fifth maximum of the double-slit pattern, which significantly reduces the intensity of the fifth maximum.
The ratio of the width of the slits to the separation between them is dependent on the distance between these minimums and maximums in the interference pattern. This information can be determined using the equations for interference and diffraction patterns.