This is a brain teaser that I created myself based on my own experience from driving to and from NY back in ’99. There may be more than one solution but I’ll give my solution eventually. Here goes.
You are driving from Moncton, NB to New York city in July. You leave Moncton, NB at 7am and arrive in NYC that evening. When you left Moncton, NB, you had a full tank of gas and you made note of your odometer reading. Everytime your car hit a half a tank of gas, you stopped at the next gas station and filled up. Everytime you get gas, you make a note of how much money it cost you to fill up. During your trip, you make several stops for food and bathroom breaks. When you arrive in NYC, you make note of how many kilometers you have travelled.
You leave NYC at 7pm the next day and drive back to Moncton arriving in Moncton the following morning (driving all night). When you left NYC you had a full tank of gas and you made note of your odometer reading. Everytime your car hit half a tank of gas, you stopped at the next gas station and filled up. Everytime you get gas, you make a note of how much money it cost you to fill up. When you arrive in Moncton, you make note of how many kilometers you have travelled.
For both trips (to and from NYC), you use the same highway, travel the same speed, and make the same amount of food and bathroom stops. The mileage travelled to NYC is within 5kms of the mileage travelled to Moncton (meaning you travelled the same distance both ways give or take 5kms). Everytime you gased up (both directions) you used regular gasoline (not supreme), and the pump prices were were relatively the same each way (within 5 cents).
When you get back to Moncton, you discover that it cost you less money in gas (about a half tanks worth) for the return trip, than it did for the original trip. You’re absolutely certain that the price of gas for the return trip was the same as going to NYC.
Why was the return trip cheaper?
(If you want my answer, click the read more and see it)
The most important word or clue in that teaser in the word July. Meaning, it’s freaking hot. The reason why it costs more to go to NYC than come home is the trip TO NYC was done in the daytime, when you run the air-conditioning in your car. Because the AC is harder on the engine, you burn more gas. On a long trip like that, you’ll burn a lot of gas using the AC.
The trip home was overnight when it’s not so hot so there wasn’t a need to use the AC. Hence, cheaper gas mileage.
A true story I discovered on my own way back when.
