The local lottery sets up a game wherein a player has a chance of collecting $750.

The player must choose a 3-digit number and if it matches, the player receives $750
It costs $1 to play the game.
What is the expected profit (or loss) for each player.

This is not statistics.

Expected profit= winvalue*probability - cost*probability.

There is one chance in 999 of winning. There are 998 chances of losing. Correct?

expected profit=750*1/999 - 1*998/999

It reminds me of the lotto, with over 1/2 the money being raked off for political uses, it is hard to justify gambling except to "help education", as the expected value of playing is greatly negative.