Explain a real world example of a combination where repetition is allowed. You need to EXPLAIN WHY, not just give an example.

Combinations refer to the combination of n things taken k at a time without repetition. To refer to combinations in which repetition is allowed, the terms k-selection, k-multiset, or k-combination with repetition are often used.

Step-by-step explanation:

in smaller cases it is possible to count the number of combinations. For example given three fruit, say an apple, orange and pear, there are three combinations of two that can be drawn from this set: an apple and a pear; an apple and an orange; or a pear and an orange.

your answer would be 10x - 1