Is "unlikely" the same as lucky?

I gave an exam today with population growth problems. The answer to the first problem was 245. The answer to the second problem was -254. I made up all of the numbers and didn't know the answers before giving the test. While I could have figured out that 0.53x800x(1-800/2000) was the inverse of 0.53x800x(1-800/500), the likelihood that I would arbitrarily pick three numbers (800, 500, and 2000) that would give identical inverse results is well, statistically very very unlikely.

Meanwhile, the chem prof. did a demonstration in which 1 g of something led to 1 L of gas (or .1, I forget), a situation which only occurs under specific temperature and pressure, which he was not controlling. Also very very unlikely.

So maybe it's my day to buy a power ball ticket. Yet somehow, having done something statistically improbable with numbers doesn't make me feel particularly lucky at all. Lucky must be more than unlikely.

But is does make my grading one step easier.