How many six digit odd numbers can be formed from the digits 0, 2, 3, 5, 6, 7, 8, and 9 (repetition not allowed)?
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1
Just keep the odd numbers in a row at first
Next keep different numbers in a row
Each should not be same with each other
Next keep different numbers in a row
Each should not be same with each other
sonu2006:
I can't understand
Means select six odd numbers and keep them in a row
Answered by
1
Total number of digits to be used 8
Unit digit can hold any of the 4-digits; 3,5,7 or 9 for an odd digit.
And 0 can't be the leading digit of the 6-digit number.
Therefore, (7*6*5*4*3*4)-(Number of cases when 0 is the 6-digit).
Therefore, (7*6*5*4*3*4)-(6*5*4*3*4)
=10080-1440
=8640
Unit digit can hold any of the 4-digits; 3,5,7 or 9 for an odd digit.
And 0 can't be the leading digit of the 6-digit number.
Therefore, (7*6*5*4*3*4)-(Number of cases when 0 is the 6-digit).
Therefore, (7*6*5*4*3*4)-(6*5*4*3*4)
=10080-1440
=8640
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