There are times when you should request copies of your records: 1  Permanent Change of Station. 2  Deploying. 3  Retiring.
0. EXPERT ANSWER. Double coincidence of wants refers to a situation in a barter system where the goods or services offered by a seller are exactly the same as that required by a buyer and vice versa.
Rating Newest Oldest. Best Answer: In conventional usage a double mutation is two single mutations. For example, I am working with a gene. In our lab we made a single mutation in that gene, and then tested it to see what effect that had on the process we study.Then, we took the original gene and made a different mutation elsewhere in the gene, and tested that mutant.Now, we are also making the double mutant which will have both of the single mutations and will test it to see what effect both mutations have when present at the same time.hen, we took the original gene and made a different mutation elsewhere in the gene, and tested that mutant. Now, we are also making the double mutant which will have both of the single mutations and will test it to see what effect both mutations have when present at the same time.