Question 270462: How many license plates are possible to make if (a) digits and letters can be repeated, (b) and digits and letters cannot be repeated.
a) 4 digits followed by 2 letters
b)6 digits followed by 3 letters
Answer by papugai(18)   (Show Source):
You can put this solution on YOUR website! How many license plates are possible to make if (a) digits and letters can be repeated, (b) and digits and letters cannot be repeated.
a) 4 digits followed by 2 letters
b)6 digits followed by 3 letters
Label a digit as d and letter as l
a) ddddll
If you can repeat:
nine options for each d and 26 options for each l
9*9*9*9*26*26=4435236
Cannot repeat:
nine options for the first d, eight for the second, seven for the third, and six for the fourth; 26 for the first d and 25 for the second
multiply it all:
9*8*7*6*26*25=1965600
b)ddddddlll
Repeat:
Use same way (nine options for each digit and 26 for each letter)
9*9*9*9*9*9*26*26*26=9340607016
Cannot repeat:
Same pattern:
9*8*7*6*5*4*26*25*24=943488000
Please let me know how helpful was this
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