Someone wishes to design a lottery according to the following rules: Each ticket costs $5, there are three prizes $10, $100, and $1,000. The probability of the $10 prize is 1/5. The probability of the $100 prize is 1/100. A million tickets will be sold each month. What should be probability be for the $1,000 prize, if they would like to earn one million dollars per month on average?