question: Ralph has a record store where people can trade their own records for new ones. People can trade 2 old records for 1 new one. 5 people come in with old records and leave with 7 new records between them. How many old records did the 5 people bring in?
answer: People can bring in 2 old records = get 1 new record.
  5 people come in with old records and leave with 7 new records, 7 new records x 2 old records traded for each = <<7*2=14>>14 old records that the 5 people brought in.
  #### 14