PSLE The ratio of the number of windbreakers to that of skirts in a shopping centre was 12 : 7 in the end. After 145 skirts were sold, the ratio of the number of windbreakers to that of skirts became 11 : 4. What was the total number of windbreakers and skirts in the shopping centre in the end?
|
Windbreakers |
Skirts |
Total |
Before |
12x11 = 132 u |
7x11 = 77 u |
209 u |
Change |
|
- 145 |
|
After |
11x12 = 132 u |
4x12 = 48 u |
180 u |
The number of windbreakers remains unchanged. Make the number of windbreakers the same.
LCM of 11 and 12 is 132.
Number of skirts sold
= 77 u - 48 u
= 29 u
1 u = 145 ÷ 29 = 5
Total number of windbreakers and skirts in the end
= 132 u + 48 u
= 180 u
= 180 x 5
= 900
Answer(s): 900