On a shelf, there were 170 skirts and jackets. Bobby spilt orange juice on the shelf and stained 50% of the jackets and 10% of the skirts. If 149 skirts and jackets were still clean, how many clean jackets were there?
| |
Skirts |
Jackets |
Total |
| Stained |
1 u |
1 p |
21 |
| Clean |
9 u |
1 p |
149 |
| Total |
10 u |
2 p |
170 |
50% =
50100 =
12 10% =
10100 =
110 Number of stained clothes
= 170 - 149
= 21
9 u + 1 p = 149
1 p = 149 - 9 u --- (1)
1 u + 1 p = 21
1 p = 21 - 1 u --- (2)
(2) - (1)
21 - 1 u = 149 - 9 u
9 u - 1 u = 149 - 21
8 u = 128
1 u = 128 ÷ 8 = 16
Number of clean jackets is the same as the number of stained jackets.
Number of clean jackets
= 21 - 1 u
= 21 - 16
= 5
Answer(s): 5
