Irene gave 10% of her collection of stamps to Rachel thereby increasing Rachel's collection by 25%. If Irene had 45 stamps left, how many stamps did Rachel have at first?
| |
Irene's stamps |
Rachel's stamps |
| Before |
100% |
100 u |
| Change |
- 10% |
+ 10% = + 25 u |
| After |
90% |
125 u |
90% of Irene's collection = 45
1% of Irene's collection = 45 ÷ 90 = 0.5
10% of Irene's collection = 10 x 0.5 = 5
25 u of Rachel's collection = 5
1 u of Rachel's collection =
520 = 0.2
100 u of Rachel's collection = 100 x 0.2 = 20
Answer(s): 20
