On a shelf, there were 88 shirts and cardigans. Ethan spilt tea on the shelf and stained 50% of the cardigans and 10% of the shirts. If 68 shirts and cardigans were still clean, how many clean cardigans were there?
| |
Shirts |
Cardigans |
Total |
| Stained |
1 u |
1 p |
20 |
| Clean |
9 u |
1 p |
68 |
| Total |
10 u |
2 p |
88 |
50% =
50100 =
12 10% =
10100 =
110 Number of stained clothes
= 88 - 68
= 20
9 u + 1 p = 68
1 p = 68 - 9 u --- (1)
1 u + 1 p = 20
1 p = 20 - 1 u --- (2)
(2) - (1)
20 - 1 u = 68 - 9 u
9 u - 1 u = 68 - 20
8 u = 48
1 u = 48 ÷ 8 = 6
Number of clean cardigans is the same as the number of stained cardigans.
Number of clean cardigans
= 20 - 1 u
= 20 - 6
= 14
Answer(s): 14
