Question 159
a. Show that there is no positive integer $n$ such that the sum of the digits of $10^n + 9n$ is divisible by $2007$.
b. Find at least one positive integer $n$ such that the sum of the digits of $10^n + 9n$ equals $2008$.
b. Find at least one positive integer $n$ such that the sum of the digits of $10^n + 9n$ equals $2008$.