In one restaurant, the round table can seat 7 customers and the rectangular table can seat 3 customers. During the buffet, all the tables in the restaurant were occupied. The number of each type of tables in the restaurant is more than 5 and less than 12. If there were 87 customers, find
(a) the number of rectangular tables
(b) the number of round tables
Rectangular tables |
Number of customers around rectangular tables |
Round tables |
Number of customers around round tables |
Total number of customers |
6 |
6 x 3 = 18 |
6 |
6 x 7 = 42 |
18 + 42 = 60 (x) |
7 |
7 x 3 = 21 |
8 |
8 x 7 = 56 |
21 + 56 = 77 (x) |
8 |
8 x 3 = 24 |
9 |
9 x 7 = 63 |
24 + 63 = 87 (✓) |
(a)
Number of rectangular tables = 8
(b)
Number of round tables = 9
Answer(s): (a) 8; (b) 9