% is used for getting the remainder after the division of any two numbers.

The output will be "2" :

x has been assigned a value of 3 and num of 17. Now, we divide num by x or 17 by 3, the answer would give the remainder after the division and i.e. 2;

% is used for getting the remainder after the division of any two numbers. So :

3 x 5 = 15;
17 - 15 = 2;