Question

Assume that a postal code consists of 6 characters. Each character can be any letter from A to Z or any numeral from 0 to 9. How many postal codes are possible in this situation?

Answer 1

Answer:

$36^6$ postcodes

Step-by-step explanation:

Think of the post code as a combination lock

[?] [?] [?] [?] [?] [?]

If letters a numbers are allowed, each character can be A-Z and 0-9.

There are 26 letters, and 10 different digits

26 + 10 = 36 characters

Each block (I illustrated above) can be any of the 36 characters

If you have 2 blocks, you have a combination of

36 x 36 characters — which is the same as $36^2$

With 3 blocks: $36^3$

and so forth...

If your post code is made of 6 'blocks' it can be any combination of

$36^6$