Main resource: .
What is Modular Arithmetic? Where \(A\) and \(B\) are integers, we can write:
$$ \frac{A}{B} = Q \text{ remainder } R $$
Using the same \(A, B, Q, \text{ and } R\) as above, we have:
$$ A \text{ mod } B = R $$
\(A \text{ mod } B\) can be visualized as taking \(A\) steps on a clock that runs from \(0\) to \(B-1\). If the number is positive we step clockwise, if it’s negative we step counterclockwise....
Problem Statement You are given the following information, but you may prefer to do some research for yourself:
1 Jan 1900 was a Monday. Thirty days has September, April, June and November. All the rest have thirty-one, Saving February alone, Which has twenty-eight, rain or shine. And on leap years, twenty-nine. A leap year occurs on any year evenly divisible by 4, but not on a century unless it is divisible by 400....