Mary ate 4 1/2 pears and Camie ate 7 2/4 pears. If they finished all the pears in a box, how many pears were in the box?

11 pears
11 1/2 pears
11 1/4 pears
12 pears

To find the total number of pears, we need to add Mary's and Camie's numbers together.

First, we need to convert the mixed fractions to improper fractions.

4 1/2 = 4 + 1/2 = 8/2 + 1/2 = 9/2
7 2/4 = 7 + 2/4 = 28/4 + 2/4 = 30/4

Now we can add the fractions together: 9/2 + 30/4 = (18 + 30) / 4 = 48/4 = 12

Therefore, there were 12 pears in the box. Answer: \boxed{12 \text{ pears}}

To find out how many pears were in the box, we need to add up the amounts that Mary and Camie ate.

Mary ate 4 1/2 pears, which can be written as 4.5 pears.

Camie ate 7 2/4 pears, which can be simplified to 7.5 pears.

Now, adding Mary's and Camie's quantities together:

4.5 + 7.5 = 12

Therefore, there were 12 pears in the box.

To find out how many pears were in the box, we need to add the number of pears Mary ate and the number of pears Camie ate.

Mary ate 4 1/2 pears, which can also be written as 4 + 1/2 = 4.5 pears.

Camie ate 7 2/4 pears, which can also be written as 7 + 2/4 = 7.5 pears.

Now, we can add the number of pears Mary and Camie ate to find the total:

4.5 + 7.5 = 12 pears.

Therefore, there were 12 pears in the box. So, the correct answer is option D - 12 pears.