PSLE The ratio of the number of skirts to that of sweaters in a factory outlet was 5 : 2 at first. After 21 sweaters were sold, the ratio of the number of skirts to that of sweaters became 4 : 1. What was the total number of skirts and sweaters in the factory outlet at first?
|
Skirts |
Sweaters |
Total |
Before |
5x4 = 20 u |
2x4 = 8 u |
28 u |
Change |
|
- 21 |
|
After |
4x5 = 20 u |
1x5 = 5 u |
25 u |
The number of skirts remains unchanged. Make the number of skirts the same.
LCM of 4 and 5 is 20.
Number of sweaters sold
= 8 u - 5 u
= 3 u
1 u = 21 ÷ 3 = 7
Total number of skirts and sweaters at first
= 20 u + 8 u
= 28 u
= 28 x 7
= 196
Answer(s): 196