$\text{Let length of the screen on which fringes are obtained is L}$

$\text{Then fringe width is } \beta = \frac{L}{92} = \frac{\lambda D}{d}$

$\text{Let new wavelength is }\lambda' \text{and number of fringes are n}$

$Then \frac{\lambda D}{d} = \frac{L}{n}$

$\Rightarrow n = \frac{92\times \lambda}{\lambda'} = 99$