Question

A company gives each clent a unique

account number containing four letters
followed by three digits. How many
account numbers are possible

Answer 1

Explanation:

so, we have 4 positions with letters.

that means we have 26 possibilities per position.

that makes 26⁴ possibilities there.

and then we have 3 positions with digits.

the means 10 possibilities per position, and so 10³ = 1000 possibilities there.

the total number of possible different account numbers is then

26⁴ × 1000 = 456,976,000