Answer: The prime factorization of 1001 is 7*11*13, so with the constraint that the tables seat between 2 and 19 guests, we can use tables that seat either 7, 11, or 13 guests.
For tables that seat 7, the caterer would need 11*13 = 143 tables.
For tables that seat 11, the caterer would need 7*13 = 91 tables.
For tables that seat 13, the caterer would need 7*11 = 77 tables
Step-by-step explanation:
hopefully this is right