SOLUTION: The numbers 1,2,3,4,5,6,7,8, and 9, four different numbers are selected to form a four-digit number
How many four-digit numbers less than 2,000 can be formed?
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-> SOLUTION: The numbers 1,2,3,4,5,6,7,8, and 9, four different numbers are selected to form a four-digit number
How many four-digit numbers less than 2,000 can be formed?
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Question 1173260: The numbers 1,2,3,4,5,6,7,8, and 9, four different numbers are selected to form a four-digit number
How many four-digit numbers less than 2,000 can be formed? Answer by ikleyn(52780) (Show Source):
"Less than 2,000" means that the first digit is " 1 " (thousand's digit).
So, first digit is fixed; it is the digit " 1 ".
In the rest 3 positions, any of 8 digits from 2 to 9 can be.
It gives 8*8*8 = = 512 opportunities and 512 possible 4-digit numbers,
under given condition.
Solved.
This solution is produced assuming that repeating is allowed.
If repeating is not allowed, then the answer is 8*7*6 = 336.
