The number of durian cakes on display at a cafe was
45 of the number of wafers on display. After 19 durian cakes were bought and the staff added another 45 wafers, the number of wafers was four times the number of durian cakes. The last group of customers bought 4 wafers each, finishing all the wafers on display. How many customers were there in the last group?
| |
Durian cakes |
Wafers |
| Before |
4 u |
5 u |
| Change |
- 19 |
+ 45 |
| After |
4 u - 19 |
5 u + 45 |
Comparing durian cakes
and wafers
in the end |
1 |
4 |
The number of wafers was four times the number of durian cakes in the end.
Number of wafers in the end
= 4(4 u - 19)
= 16 u - 76
16 u - 76 = 5 u + 45 16 u - 5 u = 76 + 4511 u = 121
1 u = 121 ÷ 11 = 11Number of wafers in the end= 5 u + 45= 5 x 11 + 45= 100Number of customers in the last group= 100 ÷ 4= 25 Answer(s): 25 
