EXAMPLE 3.3.9
Gomer's Auto Body Shoppe is still trying to unload some surplus paint by offering the following special deals:
For $99 you get a two-tone paint job, using one color for the car's top and a different color for the body.
For $129 you get a three-tone paint job, using one color for the car's top, a different color for the body, and a third color for the hub caps.
The available colors are:
1. hot pink
2. puke green
3. Gator orange
4. flaming chartreuse
How many different color schemes are possible?
A. 24
B. 36
C. 27
D. none of these
SOLUTION
A paint job will be either two-tone or three-tone, so the number of possible paint schemes will be the number of possible two-tone paint schemes plus the number of possible three-tone paint schemes.
Number of two-tone paint schemes
Choosing a two-tone paint scheme requires that we make two dependent decisions:
1. Choose color for top: 4 options
2. Choose color for body: 3 options
The number of two-tone paint schemes is
(4) times (3) = 12
Number of three-tone paint schemes
Choosing a three-tone paint scheme requires that we make three dependent decisions:
1. Choose color for top: 4 options
2. Choose color for body: 3 options
3. Choose color for hub caps: 2 options
The number of three-tone paint schemes is
(4) times (3) times (2) = 24
Thus, the total number of paint possible paint schemes is 12 + 24 = 36.