A light source, width emits two wavelengths $\lambda
1
= 400 nm and \lambda
2
= 600 nm, is used in a Young's double-slit experiment. If recorded fringe widths for \lambda
1
and \lambda
2
are \beta
1
and \beta$
2
and the number of fringes for them within a distance y on one side of the central maximum are m
1
and m
2
, respectively, then