Question

In 1963, the United States Postal Service started using ZIP (Zone Improvement Plan) codes. Each ZIP code is a sequence of five digits. How many different U.S. ZIP codes are possible?

Answer 1

There are 5 slots where you would put a number.

To find the possibilities you would multiply, you would set it up something like this:

_ * _ * _ * _ * _

There are 10 1 digit numbers: 0,1,2,3,4,5,6,7,8,9 , So in each slot there are 10 possible numbers, so in each blank you would put a 10.

Now you try to finish it.

Answer 2

100,000?

Answer 3

Yea.

Answer 4

And this process is how you do other problems. If you have to find out how many possible ways to do something, I do the lines for each possible slot, then find out how many options there are in each slot, and it's always multiplication.