Answer:
D. 56
Step-by-step explanation:
The general solution for the number of combinations with repetition is represented by the following expression:
[tex]x = \frac{(n + r - 1)!}{r!\cdot (n-1)!}[/tex] (1)
Where:
[tex]n[/tex] - Total number of elements.
[tex]r[/tex] - Number of the sample.
If we know that [tex]n = 6[/tex] and [tex]r = 3[/tex], then the number of combinations with repetition:
[tex]x = \frac{(6+3-1)!}{3!\cdot (6-1)!}[/tex]
[tex]x = 56[/tex]
Hence, correct answer is D.
