SOLUTION: How many different two digit positive integers can be formed from the digits:0, 1, 2, 3, 4, 5, 6, 7, 8, 9. (i) When repetition is not allowed, (ii) When repetition is allowed.

Question 490901: How many different two digit positive integers can be formed from the
digits:0, 1, 2, 3, 4, 5, 6, 7, 8, 9. (i) When repetition is not allowed,
(ii) When repetition is allowed.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
How many different two digit positive integers can be formed from the
digits:0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
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Note: 0 cannot be the leftmost digit.
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(i) When repetition is not allowed,
Ans: 9*9 = 81 2-digit integers
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(ii) When repetition is allowed.
Ans: 9*10 = 90 2 digit integers
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Cheers,
Stan H.
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