Question

PLEASE HELP ME WITH THIS ONE QUESTION

How many combinations with repetition are allowed if n = 6 and r = 3?

A) 27
B) 20
C) 18
D) 56

Answer 1

D. 56

Explanation:

The general solution for the number of combinations with repetition is represented by the following expression:

`x = ((n + r - 1)!)/(r!\cdot (n-1)!)` (1)

Where:

`n` - Total number of elements.

`r` - Number of the sample.

If we know that
`n = 6` and
`r = 3`, then the number of combinations with repetition:

`x = ((6+3-1)!)/(3!\cdot (6-1)!)`

`x = 56`

Hence, correct answer is D.