This problem is about the rate of the current. It's important to know that refers to the quotient between the electric charge and the time, that's the current rate.
Where Q = 2.0×10^−4 C and t = 2.0×10^−6 s. Let's use these values to find I.
As you can observe above, the division of the powers was solved by just subtracting their exponents.
Therefore, the rate of the current flow is 1.0×10^2 A.