How many odd five-digit counting numbers can be formed by choosing digits from the set [1,2,3,4,5,6,7] if digits can be repeated?
The 5 digit number will end in either 1, 3, 5 or 7
Since digits can be repeated we have 7 choices for each of the 4 leading positions and 4 choices for the ending digit
So....the total number of odd five-digit countig numbers =
7^4 * 4 =
A different perspective...just an FYI
75 possible numbers 4 out of 7 are odd 75 x 4/7 = 9604 (as Chris calculated)
Cal has told me that this wasn't actually her question.
The system is sometimes capturing her username and assigning it to guest questions that have just been posted.
I assume she is on shared wifi or something like that.
Anyway she says she is glad it happened this time because she learned a lot from EP and Chris who so kindly answered this question.
It is so nice to know that we have genuine learners here. Thanks Cal.