1. example> how many 3 digit numbers can be formed by using the digits 3,4, 5 and 6 without repetiing how many of these are even?

Asked by  | 8th Apr, 2012, 04:05: PM

Expert Answer:

For forming 3 digits number out of 3,4,5,6
For the first place, we have 4 options, after we have choosen any number out of given 4 numbers, we are left with 3 options for the second digit and finally we have 2 choices for the last digit of the three digit number.
Hence, total number of 3 digit numbers without repetition= 4x3x2= 24
Out of these 24 numbers, 6 numbers will end in 3, 6 will end in 4, 6 will end in 5 and last 6 will end in 6.
So the numbers of even cases will be when the end is in wither 4 or 6
So that makes total number of even digits as 6+6=12
So 12 numbers will be even out of total 24 numbers

Answered by  | 9th Apr, 2012, 06:34: PM

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