On a shelf, there were 60 sweaters and shirts. Justin spilt orange juice on the shelf and stained 50% of the shirts and 20% of the sweaters. If 36 sweaters and shirts were still clean, how many clean shirts were there?
| |
Sweaters |
Shirts |
Total |
| Stained |
1 u |
1 p |
24 |
| Clean |
4 u |
1 p |
36 |
| Total |
5 u |
2 p |
60 |
50% =
50100 =
12 20% =
20100 =
15 Number of stained clothes
= 60 - 36
= 24
4 u + 1 p = 36
1 p = 36 - 4 u --- (1)
1 u + 1 p = 24
1 p = 24 - 1 u --- (2)
(2) - (1)
24 - 1 u = 36 - 4 u
4 u - 1 u = 36 - 24
3 u = 12
1 u = 12 ÷ 3 = 4
Number of clean shirts is the same as the number of stained shirts.
Number of clean shirts
= 24 - 1 u
= 24 - 4
= 20
Answer(s): 20
