On a shelf, there were 118 skirts and sweaters. Ivan spilt hot soy milk on the shelf and stained 50% of the sweaters and 10% of the skirts. If 95 skirts and sweaters were still clean, how many stained sweaters were there?
| |
Skirts |
Sweaters |
Total |
| Stained |
1 u |
1 p |
23 |
| Clean |
9 u |
1 p |
95 |
| Total |
10 u |
2 p |
118 |
50% =
50100 =
12 10% =
10100 =
110 Number of stained clothes
= 118 - 95
= 23
9 u + 1 p = 95
1 p = 95 - 9 u --- (1)
1 u + 1 p = 23
1 p = 23 - 1 u --- (2)
(2) - (1)
23 - 1 u = 95 - 9 u
9 u - 1 u = 95 - 23
8 u = 72
1 u = 72 ÷ 8 = 9
Number of stained sweaters
= 23 - 1 u
= 23 - 9
= 14
Answer(s): 14
