In one coffee shop, the rectangular table can seat 10 customers and the round table can seat 3 customers. During the buffet, all the tables in the coffee shop were occupied. The number of each type of tables in the coffee shop is more than 4 and less than 11. If there were 111 customers, find
(a) the number of round tables
(b) the number of rectangular tables
Round tables |
Number of customers around round tables |
Rectangular tables |
Number of customers around rectangular tables |
Total number of customers |
5 |
5 x 3 = 15 |
5 |
5 x 10 = 50 |
15 + 50 = 65 (x) |
6 |
6 x 3 = 18 |
8 |
8 x 10 = 80 |
18 + 80 = 98 (x) |
7 |
7 x 3 = 21 |
9 |
9 x 10 = 90 |
21 + 90 = 111 (✓) |
(a)
Number of round tables = 7
(b)
Number of rectangular tables = 9
Answer(s): (a) 7; (b) 9