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Post logical mathematical reasoning problems here.

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AdrenalineXV:
Question 1:
With the digits 7, 3, 5, 6; 24 four-digit numbers can be formed. From these 24 numbers, the quantity of odd numbers is the same as a:

So, I know that 4! / (4-4)! = 24. There are 3 odd numbers and one even number. What is next?

Regards.

[MAF]Agus:

[MAF]mooman:
I'm so confused.

AdrenalineXV:

--- Quote from: [MAF]mooman on April 23, 2015, 03:19:26 am ---I'm so confused.

--- End quote ---

mooman, Agus:

It is the same as above: If 24 numbers (four-digit each one) can be formed with: 7, 3, 5 ,6. Find the quantity of odd numbers from these.

Regards.

[MAF]mooman:
Anything multiplied by 10, 100 or 1000 is even and adding an even number to an odd/even number results in an odd/even number. Therefore only the last digit matters and every number will be odd except for those ending in 6, of which there are 3! = 6.

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