I have a prob question that i need help with, thanks a lot

"suppose people attending a party pour drinks from a bottle containing 63 ounces of vodka. suppose also that the expected size of each drink is 2oz, the standard deviation of each drink is 1/2 oz, all drinks are poured independly. whats the probability that the bottle will not be empty after 36 drinks have been poured?? "

thanks for the help