How many 7 digit numbers are there with exactly 4 odd digits and 3 even digits in them?

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Priye

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It's a 7 digit number. But there are 4 odd digits in no specified position. Rest 3 are even. A question of permutation.
 
Priye said:
It's a 7 digit number. But there are 4 odd digits in no specified position. Rest 3 are even. A question of permutation.
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How many ways can you choose which positions will hold even digits? How many ways are there to fill those with even digits? How many ways can you fill the other places with odd digits?
 
You might want to consider two cases. One where the 1st digit is even (2, 4, 6 or 8) and the other has an odd 1st digit (1, 3, 5, 7, 9)
 
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