(Solved): A double-slit interference pattern is observed on a screen 1.1m behind two slits spaced 0.25mm ...

A double-slit interference pattern is observed on a screen $1.1\mathrm{m}$ behind two slits spaced $0.25\mathrm{mm}$ apart. 7 bright fringes span a distance of $1.7\mathrm{cm}$. What is the wavelength of the light? What is the wavelength of the light? $\mathrm{m}$ How many fringes would have been observed if the wavelength was $4.4\mathrm{E}?7\mathrm{m}$ instead? (Give an whole number)