How many electrons must be removed from an electrically neutral silver dollar to give it a charge of +2.4 μc?

The total charge to be removed is -2.4 μC. The number of
electrons corresponding to this charge is
                      N = (-2.4 x 10^-6 C)/(-1.60 x 10^-19 C)
                          = 1.5 x 10^13 electrons
Therefore 1.5 x 10^13 electrons need to be removed from the neutral silver dollar.