On a shelf, there were 156 skirts and jackets. Jack spilt tea on the shelf and stained 50% of the jackets and 10% of the skirts. If 138 skirts and jackets were still clean, how many clean jackets were there?
| |
Skirts |
Jackets |
Total |
| Stained |
1 u |
1 p |
18 |
| Clean |
9 u |
1 p |
138 |
| Total |
10 u |
2 p |
156 |
50% =
50100 =
12 10% =
10100 =
110 Number of stained clothes
= 156 - 138
= 18
9 u + 1 p = 138
1 p = 138 - 9 u --- (1)
1 u + 1 p = 18
1 p = 18 - 1 u --- (2)
(2) - (1)
18 - 1 u = 138 - 9 u
9 u - 1 u = 138 - 18
8 u = 120
1 u = 120 ÷ 8 = 15
Number of clean jackets is the same as the number of stained jackets.
Number of clean jackets
= 18 - 1 u
= 18 - 15
= 3
Answer(s): 3
