The velocity $\left(\mathrm{V}\right)$ of de Broglie wave is given by

$\left[\begin{array}{c}\mathrm{u}=\mathrm{Frequency}\\ \mathrm{m}=\mathrm{mass}\\ \mathrm{C}=\mathrm{Velocity} \mathrm{of} \mathrm{light}\end{array}\right]$

The De Broglie hypothesis proposes that all matter exhibits wave-like properties and relates the observed wavelength of matter to its momentum.

$\mathrm{\lambda } = \frac{\mathrm{h}}{\mathrm{mv}} \mathrm{Where} \mathrm{\lambda } \mathrm{wavelength} \mathrm{of} \mathrm{particle} \mathrm{wave}. \mathrm{v} = \mathrm{velocity} \mathrm{of} \mathrm{particle}.$

Also we know that $\mathrm{Frequency} \mathrm{u} = \frac{\mathrm{C}}{\mathrm{\lambda }} \mathrm{or} \mathrm{\lambda } = \frac{\mathrm{C}}{\mathrm{u}}$

$\frac{\mathrm{C}}{\mathrm{u}} = \frac{\mathrm{h}}{\mathrm{mv}}$

After rearranging this equation.

Velocity $\mathrm{v} = \frac{\mathrm{hu}}{\mathrm{mC}}$