PSLE The ratio of the number of jackets to that of dresses in a boutique was 2 : 1 at first. After 21 dresses were sold, the ratio of the number of jackets to that of dresses became 11 : 4. What was the total number of jackets and dresses in the boutique at first?
|
Jackets |
Dresses |
Total |
Before |
2x11 = 22 u |
1x11 = 11 u |
33 u |
Change |
|
- 21 |
|
After |
11x2 = 22 u |
4x2 = 8 u |
30 u |
The number of jackets remains unchanged. Make the number of jackets the same.
LCM of 11 and 2 is 22.
Number of dresses sold
= 11 u - 8 u
= 3 u
1 u = 21 ÷ 3 = 7
Total number of jackets and dresses at first
= 22 u + 11 u
= 33 u
= 33 x 7
= 231
Answer(s): 231