How many permutations of the letters a, b, c, d, e, f, g either begin with an a or end with an a?

There are 7 letters to arrange:

if they have to start with a, the remaining arrangement is 6! starting with a

Same logic if they end by a:

So the total number of permutation is 6! + 6! = 2 (6!) = 1440 permutation