How Would I Answer This Stats Question?

The student senate is sponsoring a car raffle to raise money to buy a playground equipment for disadvantage children. The senate received a donated car worth $7,000 and sold 3,750 raffle tickets at $5 each.

a) If you buy 10 tickets, what is the probability that you will win the car? What is the probability that you will not win the car?

b) Compute your expected earnings.

c) How much did you contribute to the playground fund?

Suggestion:

a)
There are a total of 3750 tickets. You have 10 tickets.
The probability that you win is 10/3750

The probability that you don't win is 3740/3750.

b)
The probability that you win times 7000 plus the probability that you don't win times 0.
(10/3750)*7000 + (3740/3750)*0
(10/3750)*7000
=$18.67

c)
You bought 10 tickets each worth 5 dollars so you spent $50.

Now your expected earning is $18.67

50-18.67 = 31.33

You contributed $ 31.33