Penelope had $100 less than Irene. Irene spent 0.4 of her money and Penelope spent 30% of her money. In the end, Irene and Penelope had the same amount of money left. Find the amount of money that Irene had at first.
| |
Penelope |
Irene |
Comparing Irene
and Penelope at first |
|
100 more |
| Before |
10x3 =
30 u |
5x7 =
35 u |
| Change |
- 3x3 =
- 9 u |
- 2x7 =
- 14 u |
| After |
7x3 =
21 u |
3x7 =
21 u |
0.4 =
410 =
25 30% =
30100 =
310 Penelope and Irene had the same amount of money in the end. Make the amount that each had in the end the same. LCM of 3 and 7 is 21.
Amount that Penelope had less than Irene at first
= 35 u - 30 u
= 5 u
5 u = 100
1 u = 100 ÷ 5 = 20
Amount that Irene had at first
= 35 u
= 35 x 20
= $700
Answer(s): $700
