PSLETina and Erika went shopping together with a total amount of $85.80. Tina spent 2 times as much as Erika. The amount Erika had left was $14 more than what she had spent. She had 2 times as much money left as Tina.
(a) How much money did Erika spend?
(b) How much money did Tina have at first?
|
Tina |
Erika |
Total |
Before |
2.5 u + 7 |
2 u + 14 |
85.80 |
Change |
- 2 u |
- 1 u |
|
After |
0.5 u + 7 |
1 u + 14 |
|
(a)
Total amount that Tina and Erika had at first
= (2.5 u + 7) + (2 u + 14)
= 2.5 u + 2 u + 7 + 14
= 4.5 u + 21
4.5 u + 21 = 85.8
4.5 u = 85.8 - 21
4.5 u = 64.8
1 u = 64.8 ÷ 4.5 = 14.4
Amount that Erika had at first
= 1 u
= $14.40
(b)
Amount that Tina had at first
= 2.5 u + 7
= (2.5 x 14.4) + 7
= 36 + 7
= $43
Answer(s): (a) $14.40; (b) $43