Ivory and Abi have some money. If Ivory spends $2, she will have
45 as much money as Abi. If Abi spends $2, Ivory will have
67 as much money as Abi. How much money does Ivory have?
|
Case 1 |
Case 2 |
|
Ivory |
Abi |
Ivory |
Abi |
Before |
4 u + $2 |
5 u |
6 p |
7 p + $2 |
Change |
- $2 |
|
|
- $2 |
After |
4 u |
5 u |
6 p |
7 p |
The amount that Ivory has at first in Case 1 and Case 2 is the same.
4 u + 2 = 6 p
4 u = 6 p - 2 --- (1)
The amount that Abi has at first in Case 1 and Case 2 is the same.
5 u = 7 p + 2 --- (2)
Make u the same.
(1)
x 520 u = 30 p - 10 --- (3)
(2)
x 420 u = 28 p + 8 --- (4)
(3) = (4)
30 p - 10 = 28 p + 8
30 p - 28 p = 10 + 8
2 p = 18
1 p = 18 ÷ 2 = 9
Amount that Ivory has
= 6 p
= 6 x 9
= $54
Answer(s): $54