On a randomly selected day at a particular restaurant, 200 customers were categorized by their ethnic groups and their age groups, and, were summarized by counting how many of these customers belonged to each combination of ethnic group and age group. The results appear in the following table:

Ethnic Group

Age A B C D Total

young 10 17 30 18 75

middle age 6 24 17 13 60

senior 5 8 20 12 45

elderly 4 6 3 7 20

Total 25 55 70 50 200

Answer each of the following parts, by leaving your answers as fractions, if one customer was randomly selected to win a $500 gift certificate (Show your work if necessary)

The probability that the selected customer:

1. belonged to ethnic group B knowing that the customer was young
2. was middle age knowing that the customer belonged to ethnic group C
3. was young or elderly
4. was middle age or belonged to ethnic group B
5. was middle age and elderly
6. was a senior
7. belonged to ethnic group A.
8. was elderly and belonged to ethnic group D