Question

PLEASE HELP ME WITH THIS ONE QUESTION

How many combinations without repetition are possible if n = 4 and r = 3?

A) 16
B) 12
C) 3
D) 4

Answer 1

Explanation:

Answer 2

Given:

`n=4` and
`r=3`.

To find:

The combinations without repetition are possible if
`n=4` and
`r=3`.

Solution:

Combination of selecting r item from total n items is:

`^nC_r=(n!)/(r!(n-r)!)`

We have
`n=4` and
`r=3`. By using the above formula, we get

`^4C_3=(4!)/(3!(4-3)!)`

`^4C_3=(4* 3!)/(3!1!)`

`^4C_3=4`

Therefore, the correct option is D.