This exercise entails finding scenes, or parts of scenes that are each dominated by a single one of the primary and secondary colours. With each colour vary the exposure slightly (as done in the previous exercise).
For each of the series of photos below the exposure compensation is -0.7; -0.3; 0; +0.3; +0.7 when viewed from left to right.
Green
In this photo I think that the shade of green that most closely matches the colour wheel is the second one (-0.3EV)
Blue
For the blues again I would go for the second photo (-0.3EV).
Yellow
In the case of yellow I think the exposure that most closely matches the colour wheel is the 4th image (+0.3EV)
Red
In this case I think that it is the 4th image again (+0.3EV)
Purple
For me the second image best reflects the colour (-0.3EV)
Orange
Here I think the fourth or fifth, probably the fourth image best reflects the colour (+0.3EV)
What have I learned from this exercise? The first lesson was to go out and look for the primary colours, then, as with the previous lesson, appreciate the effect that exposure can have on the colour.