On a shelf, there were 90 sweaters and cardigans. Caden spilt hot tea on the shelf and stained 50% of the cardigans and 20% of the sweaters. If 60 sweaters and cardigans were still clean, how many stained cardigans were there?
| |
Sweaters |
Cardigans |
Total |
| Stained |
1 u |
1 p |
30 |
| Clean |
4 u |
1 p |
60 |
| Total |
5 u |
2 p |
90 |
50% =
50100 =
12 20% =
20100 =
15 Number of stained clothes
= 90 - 60
= 30
4 u + 1 p = 60
1 p = 60 - 4 u --- (1)
1 u + 1 p = 30
1 p = 30 - 1 u --- (2)
(2) - (1)
30 - 1 u = 60 - 4 u
4 u - 1 u = 60 - 30
3 u = 30
1 u = 30 ÷ 3 = 10
Number of stained cardigans
= 30 - 1 u
= 30 - 10
= 20
Answer(s): 20
