Probablity , Statistics, Model Complexity

You sell roses. Each rose cost 30 cents to buy and you can sell them for $10 a dozen.

1. a) How many you need to sale to break even if you bought 600 roses?
2. b) Tomorrow is holiday – there’s 20% likelihood you will sale 600 roses, 50% likelihood of selling 900 roses and 30% likelihood of selling 1200 roses. How many would you buy to maximize profit