Answer
$9.375\times 10^{19}\frac{electrons}{s}$
Work Step by Step
As we know that
$\frac{N}{\Delta t}=\frac{I}{e}$
We plug in the known values to obtain:
$\frac{N}{\Delta t}=\frac{15}{1.6\times 10^{-19}}$
$\frac{N}{\Delta t}=\frac{15}{1.6\times 10^{-19}}$
$\frac{N}{\Delta t}=9.375\times 10^{19}\frac{electrons}{s}$