if Sandra read 5 books and Deacon read 6 and Breanna read 7 and they all one same book, then that means sandra read 4 different books then Deacon and Breanna. Deacon read 5 different books then Sandra and Breanna. Breanna read 6 different books then Deacon and Sandra.
So Sandras 4 books plus Deacons 5 books plus Breannas 6 books equals up to 15 but, now you need to add the one book they all read which makes the answer 16.
