PSLE The ratio of the number of sweaters to that of windbreakers in a shopping centre was 11 : 5 in the end. After 6 windbreakers were sold, the ratio of the number of sweaters to that of windbreakers became 7 : 3. What was the total number of sweaters and windbreakers in the shopping centre in the end?
|
Sweaters |
Windbreakers |
Total |
Before |
11x7 = 77 u |
5x7 = 35 u |
112 u |
Change |
|
- 6 |
|
After |
7x11 = 77 u |
3x11 = 33 u |
110 u |
The number of sweaters remains unchanged. Make the number of sweaters the same.
LCM of 7 and 11 is 77.
Number of windbreakers sold
= 35 u - 33 u
= 2 u
1 u = 6 ÷ 2 = 3
Total number of sweaters and windbreakers in the end
= 77 u + 33 u
= 110 u
= 110 x 3
= 330
Answer(s): 330