PSLE The ratio of the number of sweaters to that of vests in a factory outlet was 11 : 7 in the end. After 40 vests were sold, the ratio of the number of sweaters to that of vests became 9 : 5. What was the total number of sweaters and vests in the factory outlet in the end?
|
Sweaters |
Vests |
Total |
Before |
11x9 = 99 u |
7x9 = 63 u |
162 u |
Change |
|
- 40 |
|
After |
9x11 = 99 u |
5x11 = 55 u |
154 u |
The number of sweaters remains unchanged. Make the number of sweaters the same.
LCM of 9 and 11 is 99.
Number of vests sold
= 63 u - 55 u
= 8 u
1 u = 40 ÷ 8 = 5
Total number of sweaters and vests in the end
= 99 u + 55 u
= 154 u
= 154 x 5
= 770
Answer(s): 770