A box contains balls numbered 1, 2, . . . , 12. Eight balls are selected at random, one at a time with replacement. Let X denote the number of distinct balls selected. What is the expected value of X

Let's start off with some basics to get you familiar with the term remainder.

7 / 3 = 2.333r   or 2 remainder 1, because 3 fits into 7 twice, with 1 left over.
7/4 = 1 remainder 3
8/4 = 2 remainder 0, however we don't say remainder 0, we just say '2'.

So 860 / 14 = 61.428 (3DP). We can then multiply 61 by 14, and that difference will be the remainder.
14* 61 = 854. 
860 - 854 = 6.

The remainder of 860 divided by 14 is 6