hey guys can any1 help with this question its really confusing.
A Canadian postal code uses six characters. The first, third, and fifth are letters, while the second, fourth, and sixth are digits. A U.S zip code contains all 5 characters, all digits.
a) How many codes are possible for each country?
b) How many more possible codes does the one country have than the other?
the answer for
a) Canada : 17 576 000
U.S : 100 000
b) 17 476 000
any idea how you get that answer?
You have a six-digit/letter long code. The letters are the 1st,3rd, and 5th ( this is why i placed a 26 in each of those places - meaning there are 26 choices for each of these 3 spots) The numbers are the 2nd,4th,6th ( this is why i placed a 10 in each of these spots- meaning there are 10 choices for each of these spots ) now following the multiplicative principle i multiplied it to get the total amount.
This is a hard question to answer unless looking at specifics. Factorials are generally used to find out how many times something can be arranged. For example the word "Factor" is 6 letters long, thus can be arranged 6! ways( instead of 26^6 which would be outrageous, we use 6! because we know which letter of the 26 represents each ). If the word factor had to start with f and end with r it could be arranged 4! times. If it is a question with more then one factor involved with numbers and letters such as the one I have solved, chances are it will be ^ and the multiplicative rule.
Does that make sense?