SOLUTION: How many numbers less than 300 can be formed from the digits 1,2,3,4 and 5 a) If repetitions are not allowed? b) repetitions are allowed?

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Question 481946: How many numbers less than 300 can be formed from the digits 1,2,3,4 and 5
a) If repetitions are not allowed?
b) repetitions are allowed?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
How many numbers less than 300 can be formed from the digits 1,2,3,4 and 5
a) If repetitions are not allowed?
left-most digit 2 ways
Remaining 2 digits: 4C2 = 6
Total: 2*6 = 12 numbers
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b) repetitions are allowed?
left-most digit: 2 ways
Remaining 2 digits: 4^2 = 16
Total: 2*16 = 32 numbers
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Cheers,
Stan H.