SOLUTION: Your bank assigns a 4-digit personal identification number (PIN). The first digit cannot be 0. How many different number combinations are possible?

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Question 1046732: Your bank assigns a 4-digit personal identification number (PIN). The first digit cannot be 0. How many different number combinations are possible?
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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In all, there are 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

Zero is prohibited in the first position.

No other restrictions.

9 options for the first position and 10 options for any of 2-nd, 3-rd and 4-th position.

The number of combinations is 9%2A10%5E3 = 9000.