Question

ashely was born on 12/22/2001. how many eight-digit codes could she make using digits in her birthday?

Answer 1

We have 8 digits:

$1,2,2,2,2,0,0,1$

So, the number of combinations is:

$C=8!=40320$

However:

2 is repeated 4 times

0 is repeated 2 times

1 is repeated 2 times

Therefore:

$T=\frac{40320}{4!\cdot2!\cdot2!}=420$

Answer:

420