Question

PLEASE HELP ME WITH THIS ONE QUESTION

Answer 1

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:

$^nC_r=\dfrac{n!}{r!(n-r)!}$

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

$^4C_3=\dfrac{4!}{3!(4-3)!}$

$^4C_3=\dfrac{4\times 3!}{3!1!}$

$^4C_3=4$

Therefore, the correct option is D.