Interview Question
From charlesreid1
My interview question:
Tetration.
Notation for progressively larger numbers.
What is the remainder when you divide the number 5 tetrated by 11?
Use the following property: $a^p mod(p)$
5 tetrated can be written as 5 to the power of 5^5^5^5 mod 10, mod 11
Simplify that mod 10 expression - 5 to any power is 5, so power simplifies to 5
Expression simplifies to 5 to the 5 mod 11, or 3125 mod 11