Really struggling with exercise 9 and 10, any help would be greatly appreciated.

The self-descriptive schema of the database you have built is as follows: BEVERAGE (code, name, size) STORE (name, area, phone) SELLS (store name, code, price) 9. Find the names of the stores that offer all beverage codes; do not use COUNT, SUM, etc. 10. Find the globally smallest absolute difference of a beverage's price from the average price for beverages of the same name, and print the respective name(s), price(s), and store(s)