PSLE The ratio of the number of blazers to that of skirts in a factory outlet was 3 : 1 at first. After 21 skirts were sold, the ratio of the number of blazers to that of skirts became 10 : 1. What was the total number of blazers and skirts in the factory outlet at first?
|
Blazers |
Skirts |
Total |
Before |
3x10 = 30 u |
1x10 = 10 u |
40 u |
Change |
|
- 21 |
|
After |
10x3 = 30 u |
1x3 = 3 u |
33 u |
The number of blazers remains unchanged. Make the number of blazers the same.
LCM of 10 and 3 is 30.
Number of skirts sold
= 10 u - 3 u
= 7 u
1 u = 21 ÷ 7 = 3
Total number of blazers and skirts at first
= 30 u + 10 u
= 40 u
= 40 x 3
= 120
Answer(s): 120