Hello

A)

1. A red, white,andblue hat. <one hat with all three colors, or three hats of different color>

2. A red, a white, and a blue hat. <three hats; three different colors>

3. Red, white,andblue hats. <many hats; two meanings>

4. The red, white, and blue hat. <same as 1), but specific; i.e., 'the'>

5. The red, the white, and the blue hat. <three hats; one red, one white, and one blue>

B)

1.The operationandthe behaviorof this machine. <both>

2. The operation and behavior of this machine. (OK)

Hope that helps.