# Exercise 8

## Primality test

Write a function that determines whether a given number is a prime number. Remember, a prime number is a (natural) number greater than 1 that is only divisible (with zero remainder) by the number 1, and itself. The first few prime numbers are 2,3,5,7,11,13,17,19,23,29, …

For now you don't have to implement a fancy algorithm for testing primeness (e.g. Sieve of Eratosthenes). For now, it's ok to implement a brute force method.

Hint: you will probably want to use the modulo operator to test
whether the remainder is zero after dividing a number n by another
number m. In Python the modulo operator is `(n % m)`

. In
MATLAB/Octave, modulo is achieved using a function `mod(n, m)`

. In R
the modulo operator is `(n %% m)`

and in C the modulo operator looks
like this: `(n % m)`

.

So for example we can test whether the number 5 is prime by testing
whether `(5 % m)`

equals 0 for m=2,3,4.