Question

A certain website requires a login password to be formed by 5 numbers from digits 1-9 followed by 2 letters from the alphabet. How many passwords can be formed if neither the digits nor the letters are repeated?

Answer 1

Explanation:

password = 5 number + 2 letters

total number = g

total letter = 26

relection and arrengment both apply here

total password = gc5 * 26c2 * 7!

= 126 x 325 x 5040

total password = 2.06388 x 10^8