A new restaurant is to contain two-seat tables and four-seat tables. Fire code limits the restaurant's maximum occupancy to 56 customers. If the owners have hired enough servers to handle 17 tables of customers, how many of each kind of table should they purchase? two-seat 7; four-seat 10 two-seat 10; four-seat 7 two-seat 12; four-seat 5 two-seat 5; four-seat 12 two-seat 6; four-seat 11 two-seat 11; four-seat 6