Explanation:
Ms Sims has two ways of putting books on rack. Either put them on the table in stacks of 10, or put them as single books.
If Ms Sims puts the books on the table in stacks of 10 then there are 2 group of 10 books and 2 single books), she can do that in the following ways:
- Group 1 of 10 books and Group 2 of 10 books and book 1 and book 2
- Group 2 of 10 books and Group 1 of 10 books and book 1 and book 2
- Group 1 of 10 books and Group 2 of 10 books and book 2 and book 1
- Group 2 of 10 books and Group 1 of 10 books and book 2 and book 1
Above are the four ways.
Now is she decides to put books as single book, there would be 22 possible ways, as there are 22 books in total.
So these 22 ways and above 4 ways will make a total of 26 ways to place the books on racks.
So we can say that there are a total of 26 ways the books can be put on rack.