Tammy went shopping with twice as much money as Erika. After Tammy spent $630, Erika had four times as much money as Tammy had left. How much more money did Tammy bring along for shopping than Erika?
|
Tammy |
Erika |
Difference |
Before |
2x4 = 8 u |
1x4 = 4 u |
4 u |
Change |
- $630 |
|
|
After |
1 u |
4 u |
|
The amount that Erika has remains unchanged at first and in the end. Make the amount that Erika has the same. LCM of 1 and 4 is 4.
Amount that Tammy spent
= 8 u - 1 u
= 7 u
7 u = 630
1 u = 630 ÷ 7 = 90
Amount that Tammy brought along more than Erika
= 8 u - 4 u
= 4 u
= 4 x 90
= $360
Answer(s): $360