On a shelf, there were 39 cardigans and hoodies. Fred spilt tea on the shelf and stained 50% of the hoodies and 20% of the cardigans. If 30 cardigans and hoodies were still clean, how many clean hoodies were there?
| |
Cardigans |
Hoodies |
Total |
| Stained |
1 u |
1 p |
9 |
| Clean |
4 u |
1 p |
30 |
| Total |
5 u |
2 p |
39 |
50% =
50100 =
12 20% =
20100 =
15 Number of stained clothes
= 39 - 30
= 9
4 u + 1 p = 30
1 p = 30 - 4 u --- (1)
1 u + 1 p = 9
1 p = 9 - 1 u --- (2)
(2) - (1)
9 - 1 u = 30 - 4 u
4 u - 1 u = 30 - 9
3 u = 21
1 u = 21 ÷ 3 = 7
Number of clean hoodies is the same as the number of stained hoodies.
Number of clean hoodies
= 9 - 1 u
= 9 - 7
= 2
Answer(s): 2
