Stuti567 wrote: Hi Brent,

Thanks a lot for your wonderful explanation.

However, I have difficulties in breaking a task into stages. For example, in this question, why can we first select the model and then the color for each model? I understand that the variety of models is less than the number of cars to be selected still I don't feel very confident about it. Is there any rule or trick to divide a task into stages?

I wouldn't say that there's a general rule. In fact, in many instances, you can arrange the stages in different ways, just as long as it makes sense.

If we were to pick the models first, we'd need to consider several different cases: All three models are Model A, all three models are Model B, 1 model A and 2 model B's, ...and so on. As you can imagine, this get complicated pretty fast.

Once we see that this route isn't working, we might try a different approach.

Cheers,
Brent