The number of blueberry cakes on display at a cafe was
34 of the number of croissants on display. After 21 blueberry cakes were bought and the staff added another 42 croissants, the number of croissants was twice the number of blueberry cakes. The last group of customers bought 7 croissants each, finishing all the croissants on display. How many customers were there in the last group?
| |
Blueberry cakes |
Croissants |
| Before |
3 u |
4 u |
| Change |
- 21 |
+ 42 |
| After |
3 u - 21 |
4 u + 42 |
Comparing blueberry cakes
and croissants
in the end |
1 |
2 |
The number of croissants was twice the number of blueberry cakes in the end.
Number of croissants in the end
= 2(3 u - 21)
= 6 u - 42
6 u - 42 = 4 u + 42 6 u - 4 u = 42 + 422 u = 84
1 u = 84 ÷ 2 = 42Number of croissants in the end= 4 u + 42= 4 x 42 + 42= 210Number of customers in the last group= 210 ÷ 7= 30 Answer(s): 30 
