Julie went shopping with thrice as much money as Cathy. After Julie spent $100, Cathy had twice as much money as Julie had left. How much less money did Cathy bring along for shopping than Julie?
| |
Julie |
Cathy |
Difference |
| Before |
3x2 =
6 u |
1x2 =
2 u |
4 u |
| Change |
- $100 |
|
|
| After |
1 u |
2 u |
|
The amount that Cathy has remains unchanged at first and in the end. Make the amount that Cathy has the same. LCM of 1 and 2 is 2.
Amount that Julie spent
= 6 u - 1 u
= 5 u
5 u = 100
1 u = 100 ÷ 5 = 20
Amount that Cathy brought along less than Julie
= 6 u - 2 u
= 4 u
= 4 x 20
= $80
Answer(s): $80
