The number of cheese cakes on display at a cafe was
34 of the number of tarts on display. After 18 cheese cakes were bought and the staff added another 42 tarts, the number of tarts was twice the number of cheese cakes. The last group of customers bought 6 tarts each, finishing all the tarts on display. How many customers were there in the last group?
| |
Cheese cakes |
Tarts |
| Before |
3 u |
4 u |
| Change |
- 18 |
+ 42 |
| After |
3 u - 18 |
4 u + 42 |
Comparing cheese cakes
and tarts
in the end |
1 |
2 |
The number of tarts was twice the number of cheese cakes in the end.
Number of tarts in the end
= 2(3 u - 18)
= 6 u - 36
6 u - 36 = 4 u + 42 6 u - 4 u = 36 + 422 u = 78
1 u = 78 ÷ 2 = 39Number of tarts in the end= 4 u + 42= 4 x 39 + 42= 198Number of customers in the last group= 198 ÷ 6= 33 Answer(s): 33 
