Answer:
8,200
Step-by-step explanation:
You have to email the list of 5000 names first and then you have also second list for emailing consists of 3900 names. The sum of both the list is equal to 8,900. But there are 700 names which are common on both lists. You have to subtract 700 from 8,900 to identify the number of unique names you have. The answer you will get after subtraction is 8,200.