Question

Please answer I’ll rate brainlyest

Answer 1

Answer:

21

Step-by-step explanation:

The answer is 21, because we use the combinations formula

7!/(7-2!)(2!) = 6x7/2 = 21

Answer 2

For this case we have that by definition:

$C (n, r) = \frac {n!} {r! * (n-r)!}$

We have to:

$n = 7\\r = 2$

Substituting:

$C (7,2) = \frac {7!} {2! * (7-2)!}$

By definition:

$7! = 7 * 6 * 5!\\2! = 2 * 1 = 2$

Substituting:

$C (7,2) = \frac {7 * 6 * 5!} {2 * 5!}\\C (7,2) = \frac {7 * 6} {2}\\C (7,2) = \frac {42} {2}\\C (7,2) = 21$

Answer:

21

Option A