On a shelf, there were 70 skirts and cardigans. Luke spilt orange juice on the shelf and stained 50% of the cardigans and 25% of the skirts. If 47 skirts and cardigans were still clean, how many clean cardigans were there?
| |
Skirts |
Cardigans |
Total |
| Stained |
1 u |
1 p |
23 |
| Clean |
3 u |
1 p |
47 |
| Total |
4 u |
2 p |
70 |
50% =
50100 =
12 25% =
25100 =
14 Number of stained clothes
= 70 - 47
= 23
3 u + 1 p = 47
1 p = 47 - 3 u --- (1)
1 u + 1 p = 23
1 p = 23 - 1 u --- (2)
(2) - (1)
23 - 1 u = 47 - 3 u
3 u - 1 u = 47 - 23
2 u = 24
1 u = 24 ÷ 2 = 12
Number of clean cardigans is the same as the number of stained cardigans.
Number of clean cardigans
= 23 - 1 u
= 23 - 12
= 11
Answer(s): 11
