Rachel gave 15% of her collection of pens to Hilda thereby increasing Hilda's collection by 20%. If Rachel had 51 pens left, how many pens did Hilda have at first?
| |
Rachel's pens |
Hilda's pens |
| Before |
100% |
100 u |
| Change |
- 15% |
+ 15% = + 20 u |
| After |
85% |
120 u |
85% of Rachel's collection = 51
1% of Rachel's collection = 51 ÷ 85 = 0.6
15% of Rachel's collection = 15 x 0.6 = 9
20 u of Hilda's collection = 9
1 u of Hilda's collection =
945 = 0.45
100 u of Hilda's collection = 100 x 0.45 = 45
Answer(s): 45
