On a shelf, there were 90 blouses and shirts. Zane spilt milk on the shelf and stained 50% of the shirts and 25% of the blouses. If 61 blouses and shirts were still clean, how many clean shirts were there?
|
Blouses |
Shirts |
Total |
Stained |
1 u |
1 p |
29 |
Clean |
3 u |
1 p |
61 |
Total |
4 u |
2 p |
90 |
50% =
50100 =
12 25% =
25100 =
14 Number of stained clothes
= 90 - 61
= 29
3 u + 1 p = 61
1 p = 61 - 3 u --- (1)
1 u + 1 p = 29
1 p = 29 - 1 u --- (2)
(2) - (1)
29 - 1 u = 61 - 3 u
3 u - 1 u = 61 - 29
2 u = 32
1 u = 32 ÷ 2 = 16
Number of clean shirts is the same as the number of stained shirts.
Number of clean shirts
= 29 - 1 u
= 29 - 16
= 13
Answer(s): 13