Question

"Some debit and credit card companies require their customers to choose personal identification numbers (PINs). Customers choose 4 digits from 10 possible digits, and does not repeat digits. How many different possible PINs are there?"

Answer 1

Answer:

5040 ways

Step-by-step explanation:

In solving this problem we will use the method of permutations.

The formula for permutation is

nPr = n!/(n-r)!

Back to our question, we are required to choose 4 digits out of 10 digits. Now in solving this:

The number of ways of selecting 4 digits from 10 digits

= 10P4

= 10!/(10-4)!

= 10!/6!

= 10x9x8x7x6!/6!

= 5040 ways

Note that 6! on the numerator cancels out 6! On the denominator.