Question $9$

For this problem, you need the total, $n,$ of all digits in your student ID$.$

For example, for the student ID $12345678,$ the total is $n=36.$

Question: How many solutions, $s,$ are there to the equation

$x_1+x_2+x_3+x_4+x_5=n$ if $x_{i}in{Z}^{?}0,1i5.$

Your answer should have two parts:

A$.$ Your calculation of the value $n,$ the sum of the digits in your student

ID$.$

B$.$ Your calculation of the number of solutions, $s,$ that add up to $n.$