Ivory and Anna have some money. If Ivory spends $3, she will have
35 as much money as Anna. If Anna spends $19, Ivory will have
67 as much money as Anna. How much money does Anna have?
| |
Case 1 |
Case 2 |
| |
Ivory |
Anna |
Ivory |
Anna |
| Before |
3 u + $3 |
5 u |
6 p |
7 p + $19 |
| Change |
- $3 |
|
|
- $19 |
| After |
3 u |
5 u |
6 p |
7 p |
The amount that Ivory has at first in Case 1 and Case 2 is the same.
3 u + 3 = 6 p
3 u = 6 p - 3 --- (1)
The amount that Anna has at first in Case 1 and Case 2 is the same.
5 u = 7 p + 19 --- (2)
Make u the same.
(1)
x 515 u = 30 p - 15 --- (3)
(2)
x 315 u = 21 p + 57 --- (4)
(3) = (4)
30 p - 15 = 21 p + 57
30 p - 21 p = 15 + 57
9 p = 72
1 p = 72 ÷ 9 = 8
Amount that Anna has
= 7 p + 19
= 7 x 8 + 19
= 56 + 19
= $75
Answer(s): $75
