An office supply store stocks two sizes of notebooks, each in five colors: blue, green, yellow, red, or pink. The store packs the notebooks in packages that contain either 4 notebooks of the same size and the same color or 4 notebooks of the same size and of 4 different colors. If the order in which the colors are packed is not considered, how many different packages of the types described above are possible?  Answers.
A) 10
B) 12
C) 20
D) 24
E) 28
First let's consider the small notebooks.   There are 5 ways to choose notebooks of the same color.   The number of ways to choose four notebooks with different colors is 5C4=5.   There are 10 different packages we can make with the small notebooks.   We can use the same process to find 10 different packages with large notebooks.   The total number of different packages is 20.   The answer is 20.
<result>C</result>
An office supply store stocks two sizes of notebooks, each in five colors: blue, green, yellow, red, or pink. The store packs the notebooks in packages that contain either 4 notebooks of the same size and the same color or 4 notebooks of the same size and of 4 different colors. If the order in which the colors are packed is not considered, how many different packages of the types described above are possible?