Risa had $70 more than Zoe. Risa spent
47 of her money and Zoe spent
67 of her money. In the end, Risa had 4 times as much as Zoe. Find the amount of money Zoe had at first.
| |
Risa |
Zoe |
Comparing Risa
and Zoe at first |
$70 more |
|
| Before |
7x4 =
28 u |
7x3 =
21 u |
| Change |
- 4x4 =
- 16 u |
- 6x3 =
- 18 u |
| After |
3x4 =
12 u |
1x3 =
3 u |
Comparing Risa
and Zoe in the end |
4x3 =
12 u |
1x3 =
3 u |
The amount that Risa had in the end is repeated. Make the amount that Risa had in the end the same. LCM of 4 and 3 is 12.
Amount that Risa had more than Zoe
= 28 u - 21 u
= 7 u
7 u = 70
1 u = 70 ÷ 7 = 10
Amount that Zoe had at first
= 21 u
= 21 x 10
= $210
Answer(s): $210
