In one coffee shop, the oval table can seat 7 diners and the round table can seat 3 diners. During dinner time, all the tables in the coffee shop were occupied. The number of each type of tables in the coffee shop is more than 3 and less than 10. If there were 67 diners, find
(a) the number of round tables
(b) the number of oval tables
Round tables |
Number of diners around round tables |
Oval tables |
Number of diners around oval tables |
Total number of diners |
4 |
4 x 3 = 12 |
4 |
4 x 7 = 28 |
12 + 28 = 40 (x) |
5 |
5 x 3 = 15 |
6 |
6 x 7 = 42 |
15 + 42 = 57 (x) |
6 |
6 x 3 = 18 |
7 |
7 x 7 = 49 |
18 + 49 = 67 (✓) |
(a)
Number of round tables = 6
(b)
Number of oval tables = 7
Answer(s): (a) 6; (b) 7