1) How many arrangements of the numbers 1, 2, 3, ..., 7 are there where the sum of any two adjacent numbers is odd?
Thanks in advance!
One question at a time thanks. Learn from the answer before you ask the next one. Melody's addition.
What have you thought about so far?
What will the 2 numbers have to be if their sum is odd? etc
Talk about your questions. This will help you figure out at least some of it by yourslef and that is how you will lean.
Please no one answer over the top of me.
+4 
