The current I is the amount of charge Q that crosses a certain point of the wire in a time [tex]\Delta t[/tex]: [tex]I= \frac{Q}{\Delta t} [/tex] In our problem, the current is [tex]I=80.0 mA=0.080 A[/tex] and the time is [tex]\Delta t=10.0 min= 600.0 s[/tex], so the total charge flowing through the cross-section of the wire is [tex]Q=I \Delta t=(0.08 A)(600.0 s)=48 C[/tex]
Each electron has a charge of [tex]q=1.6\cdot 10^{-19} C[/tex], so the total number of electron is the total charge divided by the charge of one electron: [tex]N= \frac{Q}{q}= \frac{48 C}{1.6\cdot 10^{-19}C}=3\cdot 10^{20} [/tex]
And the direction of the electron flow is opposite to the direction of the current, because for convention the current direction is taken as the direction of the positive charges, while electrons are negative charges.
