PSLE The ratio of the number of sweaters to that of vests in a boutique was 7 : 3 at first. After 65 vests were sold, the ratio of the number of sweaters to that of vests became 9 : 2. What was the total number of sweaters and vests in the boutique at first?
|
Sweaters |
Vests |
Total |
Before |
7x9 = 63 u |
3x9 = 27 u |
90 u |
Change |
|
- 65 |
|
After |
9x7 = 63 u |
2x7 = 14 u |
77 u |
The number of sweaters remains unchanged. Make the number of sweaters the same.
LCM of 9 and 7 is 63.
Number of vests sold
= 27 u - 14 u
= 13 u
1 u = 65 ÷ 13 = 5
Total number of sweaters and vests at first
= 63 u + 27 u
= 90 u
= 90 x 5
= 450
Answer(s): 450