Think of all the ways that you can have a license plate with one letter/number on it, how many ways for two letter/numbers, how many ways for 3...
and so on. Then add them together.
Hope that helps
I am alright at the questions where you are told how many objects there are, and are asked how many combinations there are of those objects. My question is what about when it says something like....
"A car liscence plate consists of up to 6 characters" with any combo of the letters a-1 and numbers 0-9"
or
A room key for a hotel has a 5 by 10 array where a hole is either punched or let solid, how many different room keys are possible."
*I'm not necessarily asking you to solve both questions, I just dont know how you do a question where it could be 1 digit on a plate or 6.
Thanks.
, will give you the number of ways that you can choose one letter or number out of 36 to put on a license plate.
Do this for the license plate with 2 elements and 3 and so on and sum them.
I think this should give you a total number of ways that you can make a license plate. (Without repeat numbers or letters)
(I am not so great at combinatorics though)
Hope this helps.
I'll rewrite straight from the text book.
"assume a car license plate consists of up to 6 characters. Each character can be any of the letters a-z, or any digit 0-9 how many license plates are possible?
plates is 223897*6116
In a Hong kong hotel a room key is a card. The card has positions for holes that form a 5 by 10 array. Each position in the array is punched or left blank. How many different keys are possible?
and for the keys is 1.126*10^15
Then characters [b]can[b] be repeated. There are 26 letters and 10 digits for a total of 36 possible characters.
There are 36 possible 1 digit character, 2 character plates, [tex]36^3[tex] 3 character plates, etc. The number of plates with up to 6 plates is . That could be calculated directly or done using the formula for a finite geometric series. I get 2238976116.
Each hole has two "positions" and there are 50 holes: = 1125899906842624 which is what you give to 4 significant figures.plates is 223897*6116
In a Hong kong hotel a room key is a card. The card has positions for holes that form a 5 by 10 array. Each position in the array is punched or left blank. How many different keys are possible?
and for the keys is 1.126*10^15