On a shelf, there were 194 shirts and sweaters. Luke spilt hot soy milk on the shelf and stained 50% of the sweaters and 10% of the shirts. If 161 shirts and sweaters were still clean, how many stained sweaters were there?
| |
Shirts |
Sweaters |
Total |
| Stained |
1 u |
1 p |
33 |
| Clean |
9 u |
1 p |
161 |
| Total |
10 u |
2 p |
194 |
50% =
50100 =
12 10% =
10100 =
110 Number of stained clothes
= 194 - 161
= 33
9 u + 1 p = 161
1 p = 161 - 9 u --- (1)
1 u + 1 p = 33
1 p = 33 - 1 u --- (2)
(2) - (1)
33 - 1 u = 161 - 9 u
9 u - 1 u = 161 - 33
8 u = 128
1 u = 128 ÷ 8 = 16
Number of stained sweaters
= 33 - 1 u
= 33 - 16
= 17
Answer(s): 17
