It's funny to find a lottery game here and there are peoples actually playing it. This is a economic forum and I assume everyone is rational. Why do ppl still buy lottery here?
We spend $10 each and the return is 7.61825 only which is the sum of the following.
0
5 * 5c1*0.1*0.9^4
20 * 5c2 * 0.1^2 * 0.9^3
200 * 5c3 * 0.1^3 * 0.9^2
2000 * 5c4 * 0.1^4 * 0.9^1
200,000 * 5c5 * 0.1^5
= 7.61825...

Therefore, don't buy lottery here!