So,there was 4 guys,3 of them put together 30 $ ,10 $ from each of them 3 , and they give it to the 4th guy and sent him to buy some beer,the beer costs 25 $ ,then the 4th guy came back and he gave to the other 3 guys a 1 $ to each of them 3 , and he left with 2 $,so it means that which of them...