00:01
Okay, so we are told that the u .s.
00:02
Postal service uses five digits in their zip codes.
00:05
So we have five places where we could put a number.
00:09
And we want to figure out how many zip codes we could make if there are no restrictions on the digits used.
00:15
So this is part a.
00:16
It's the first question we're using.
00:18
If we think about what numbers we're allowed to use, we have 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9, which is 10 different digits.
00:27
So for my first number, i have 10 possible digits.
00:29
And i'm allowed to repeat so i can use any of those 10 for the next five.
00:34
So that ends up being 10 times 10 times 10 times so i said 10 to the fifth, which is one with five zeros after it...