3. The sum of five consecutive integers is $10^{2018}$. What is the middle number?
A $10^{2013}$
B $5^{2017}$
C $10^{2017}$
D $2^{2018}$
E $2 \times 10^{2017}$
3. Eet $n$ be the middle number. Then the five numbers are $n-2, n-1, n, n+1, n+2$ and have sum $5 n=10^{2018}$.
Therefore $n=\frac{10^{2018}}{5}=\frac{10 \times 10^{2017}}{5}=2 \times 10^{2017}$.