The number of cream cakes on display at a cafe was
45 of the number of wafers on display. After 21 cream cakes were bought and the staff added another 45 wafers, the number of wafers was five times the number of cream cakes. The last group of customers bought 5 wafers each, finishing all the wafers on display. How many customers were there in the last group?
| |
Cream cakes |
Wafers |
| Before |
4 u |
5 u |
| Change |
- 21 |
+ 45 |
| After |
4 u - 21 |
5 u + 45 |
Comparing cream cakes
and wafers
in the end |
1 |
5 |
The number of wafers was five times the number of cream cakes in the end.
Number of wafers in the end
= 5(4 u - 21)
= 20 u - 105
20 u - 105 = 5 u + 45 20 u - 5 u = 105 + 4515 u = 150
1 u = 150 ÷ 15 = 10Number of wafers in the end= 5 u + 45= 5 x 10 + 45= 95Number of customers in the last group= 95 ÷ 5= 19 Answer(s): 19 
