By Laplace, the probability that you choose a specific ticket is: with n being the total number of tickets. The expected value is therefore

where is your payoff for a specific scenario. Thus, for all scenarios but the first and second price. Your expected winnings are these expected payoffs minus the price per ticket of 2 dollars. Your result will, however only have two decimal digits (that differ from zero).

For 2 there is, in my opinion, too little information given. If you again go by Laplace it would be 1/3 each event and you could again easily calculate the expected payoff by the forumla given above. This is what I would do since there is nothing else computable without any distribution function of the probability of these events.