This is all about problem solving and deductive reasoning. Start with what you know and work your way, step-by-step, to a solution.
Well, there are about 8 million people in NYC, so let’s assume that half of the population owns a car. If you take into account taxis and people that own more than one vehicle, then that means there are about 4.1 million cars. The average full-service wash is probably around 80 dollars, which means it would cost around 325 million dollars to wash every car in NYC. Plus tip of course…
If math isn’t your strong suit, don’t give an exact number. Instead, explain how you’d go about solving the problem using your analytical skills.
I would need more information to answer that question. For example, are the cars getting a full-body wash, including the interior? Do we take into account the commute workers coming in from New Jersey and other surrounding cities? Are we taking into consideration the increase in water costs from using so much of it? The answer would vary greatly depending on these factors.