There are 6 different combinations of 2 books from the group of 4 that he could choose to do.
Let's say all of the books were letters.
Books a, b, c, and d.
Different combinations include:
ab, ac, ad, bc, bd, and cd.
Answer:
It is even clearer if we put it in the chart
Ethan's mistakes in sorting the shapes into two groups are:
- Shape C does not belong to group 1 because it does not have square corners
- Shape F does not belong to group 2 because it does not have any square corners
<h3>How to spot the mistakes?</h3>
From the complete question (see attachment), the shapes are grouped using the following criteria:
- All the shapes in group 1 have 4 square corners
- All the shapes in group 2 have exactly 1 square corner
Using the above rules, Ethan's mistakes are: shapes C and F are placed in the wrong groups
Read more about sorting at:
brainly.com/question/15049854
#SPJ1
5*2=10
10*3=30
30*2=60
60*3=180
180*2=360