Wouldn't I use the permutation formula to solve this question: How many positive even integers with at most 3 digits can be created using 2,3,4,5,6, and 7??
no
you have three choices for the last digit
then 5 choices for the tens place and 4 choices for the hundreds place
but that would just be for three digit numbers, it says at least three digits, so there is more work to do
oh no, it says "at most' three digits
for three digit numbers it is \(3\times 5\times 4\) for two digit numbers it is \(3\times 5\) and for one digit numbers it is 3
add up for your answer
how come only 3 for the hundreds place?
i think for this case, the repeat numbers is allowed
so, for 3 digits number there are 6 * 6 * 3 ways for 2 digits number there are 6 * 3 ways for 1 digit number there are 3 ways
k I understand. thx again!
@satellite73 , please verify me :)
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