Tiffany and Kimberly have some money. If Tiffany spends $10, she will have
25 as much money as Kimberly. If Kimberly spends $19, Tiffany will have
57 as much money as Kimberly. How much money does Kimberly have?
| |
Case 1 |
Case 2 |
| |
Tiffany |
Kimberly |
Tiffany |
Kimberly |
| Before |
2 u + $10 |
5 u |
5 p |
7 p + $19 |
| Change |
- $10 |
|
|
- $19 |
| After |
2 u |
5 u |
5 p |
7 p |
The amount that Tiffany has at first in Case 1 and Case 2 is the same.
2 u + 10 = 5 p
2 u = 5 p - 10 --- (1)
The amount that Kimberly has at first in Case 1 and Case 2 is the same.
5 u = 7 p + 19 --- (2)
Make u the same.
(1)
x 510 u = 25 p - 50 --- (3)
(2)
x 210 u = 14 p + 38 --- (4)
(3) = (4)
25 p - 50 = 14 p + 38
25 p - 14 p = 50 + 38
11 p = 88
1 p = 88 ÷ 11 = 8
Amount that Kimberly has
= 7 p + 19
= 7 x 8 + 19
= 56 + 19
= $75
Answer(s): $75
