SOLUTION: a license plate has seven possible places how many license plates can be made if only two numbers are used example 1222121 and every slot must be filled to equal a seven digit numb
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Question 514818: a license plate has seven possible places how many license plates can be made if only two numbers are used example 1222121 and every slot must be filled to equal a seven digit number Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! I'll take a shot at this
If I settle on 2 distinct numbers, like 4 and 7
I have 2 choices for each of the 7 positions on the plate
That's possible license numbers
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Now how many pairs of numbers 0 through 9 are available?
0 can be combined with 1-9, and that's 9 numbers
1 can be combined with 2-9, and that's 8 numbers
... etc...
8 can be combined with 9 and that's 1 number
So I have
possible pairs
Each of these possible pairs can make different
plates, so different plates can be made
This is if is allowed
If it isn't, the answer is
Hope I got it
