Question

#1 At a recent math conference, lunch was provided for the participants.To be sure that there was enough food for everyone, the kitchen staff made more lunches than people attending.In fact, the ratio of prepared lunches to people was 7:5. Because they anticipated a large number of vegetarians at the conference, staff made 2 vegetarian lunches for each non vegetarian lunches.It turned out that the ratio of vegetarian lunches was 3:4.What was the ratio of vegetarian lunches to vegetarians?
Extra:Each non vegetarian ate one non vegetarian lunch.