Usha and Tiffany have some money. If Usha spends $15, she will have
25 as much money as Tiffany. If Tiffany spends $3, Usha will have
58 as much money as Tiffany. How much money does Usha have?
| |
Case 1 |
Case 2 |
| |
Usha |
Tiffany |
Usha |
Tiffany |
| Before |
2 u + $15 |
5 u |
5 p |
8 p + $3 |
| Change |
- $15 |
|
|
- $3 |
| After |
2 u |
5 u |
5 p |
8 p |
The amount that Usha has at first in Case 1 and Case 2 is the same.
2 u + 15 = 5 p
2 u = 5 p - 15 --- (1)
The amount that Tiffany has at first in Case 1 and Case 2 is the same.
5 u = 8 p + 3 --- (2)
Make u the same.
(1)
x 510 u = 25 p - 75 --- (3)
(2)
x 210 u = 16 p + 6 --- (4)
(3) = (4)
25 p - 75 = 16 p + 6
25 p - 16 p = 75 + 6
9 p = 81
1 p = 81 ÷ 9 = 9
Amount that Usha has
= 5 p
= 5 x 9
= $45
Answer(s): $45
