Two potential solutions hinging on the reply to a query; are purple, inexperienced and white the one potential colours the automobiles could possibly be? This meta-question is probably going the true take a look at of the puzzle; having the ability to spot the “gap” within the necessities given by the puzzle (that not all automobiles in the true world are both white, purple or inexperienced).

If the puzzle enforces an alternate actuality the place these three colours are the one choices even for millionaires, then the reply is

three automobiles; one white, one purple, one inexperienced.

In this case, for every of the three colours, solely

one

of the automobiles can have that shade, and due to this fact two automobiles can’t.

If we’re modelling the true actual world, then the reply is

two

automobiles, all in a shade apart from white, purple, or inexperienced, reminiscent of black, silver or blue. In this example, the identical automobiles are usually not white, not purple and never inexperienced, as a result of they’re black (or blue or silver or yellow or…).