SOLUTION: how many three-digit natural numbers greater than 330 can be formed from the digits 0,1,2,3,4,5 and 6 when each digit can be used only once?

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Question 1132628: how many three-digit natural numbers greater than 330 can be formed from the digits 0,1,2,3,4,5 and 6 when each digit can be used only once?
Answer by MathLover1(20849) About Me  (Show Source):
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how many three-digit natural numbers greater than 330 can be formed from the digits 0,1,2,3,4,5 and 6 when each digit can be used only once?

Case 1: All those between 330 and 400
Choose the first digit 1 way (as 3)
That leaves 6+unchosen digits.
Choose the second digit any of+3+way s, 4,5, or 6
That leaves 5 unchosen digits
Choose the third digit any of these 5 ways.
Answer case 1: 1%2A3%2A5+=+15 ways.
Case 2: Those greater than 400
Choose the first digit any of 3 ways, 4,5, or 6
That leaves 6 remaining unchosen digits.
Choose the second digit any of these 6 remaining unchosen digits.
That leaves+5+remaining unchosen digits.
Choose the third digit any of these 5 remaining unchosen digits.
Answer to case 2: 3%2A6%2A5+=+90 ways.
Total for both cases: 15%2B90+=+105+ways