Question 172
Consider the following operation you can perform on any positive integer $n$:
Remove the lowest digit of $n$ and add to the resulting number 4 times the removed digit.
For example, if $n = 1234$ we get $123+16 = 139$, and if $n = 7$ then we get $0+28 = 28$.
If we start with $25^{2015}$ and keep on applying the operation above 10000 times, what is the number you obtain at the end?
Remove the lowest digit of $n$ and add to the resulting number 4 times the removed digit.
For example, if $n = 1234$ we get $123+16 = 139$, and if $n = 7$ then we get $0+28 = 28$.
If we start with $25^{2015}$ and keep on applying the operation above 10000 times, what is the number you obtain at the end?