Question 1201969: Without repeating any digits, how many 4-digit numbers can be formed from the numbers {1,2,3,4,5,6}, if you only want the result to be even numbers?
Answer by ikleyn(52778)   (Show Source):
You can put this solution on YOUR website! .
Last digit (ones digit) must be one of the three possibilities 2, 4, 6.
1st digit can be any of remaining 5 digits;
2nd digit can be any of remaining 4 digits;
3rd digit can be any of remaining 3 digits;
In total, there are 3*5*4*3 = 180 such 4-digit numbers. ANSWER
Solved.
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Another reasoning is THIS:
Without restriction on parity, 6*5*4*3 = 360 numbers are possible.
Of them, exactly half, 360/2 = 180, are even numbers.
Two solutions for your satisfaction.
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