Question

PLEASE HELPPP!!! The password to my tablet consists of 4 numbers. 0-9. Order doesn't matter. Repetition is allowed. How many possible combinations are there?

Answer 1

Answer:

10,000

Step-by-step explanation:

_ _ _ _

10 options for each position

10×10×10×10 = 10000

Answer 2

Answer:

210 combinations.

Step-by-step explanation:

We have 10 total digits (0-9) and we only use 4 at a time. We can use the permutation formula $\frac{n!}{k!(n-k)!}$, and plug in 10 for n and 4 for k. This is called:

n choose k.

Plug the values in, and we get 210 permutations for the password.