a) In a survey conducted among the participants in a picnic programme, 60 people liked meat, 55 people didn't like meat, 48 didn't like fish and 25 liked meat but not fish. (1) If M and F denote the sets of people who like meat and fish respectively and U is the universal set, write the relation among n(U), n(M) and n(M). (ii) How many people were surveyed? (iii) How many people like fish but not meat? (iv) If the rest of the people who did not like meat and fish were vegetarians, find the ratio of the number of vegetarians and none-vegetarians. ​