PSLEErika and Gabby went shopping together with a total amount of $142.80. Erika spent 2 times as much as Gabby. The amount Gabby had left was $40 more than what she had spent. She had 2 times as much money left as Erika.
(a) How much money did Gabby spend?
(b) How much money did Erika have at first?
|
Erika |
Gabby |
Total |
Before |
2.5 u + 20 |
2 u + 40 |
142.80 |
Change |
- 2 u |
- 1 u |
|
After |
0.5 u + 20 |
1 u + 40 |
|
(a)
Total amount that Erika and Gabby had at first
= (2.5 u + 20) + (2 u + 40)
= 2.5 u + 2 u + 20 + 40
= 4.5 u + 60
4.5 u + 60 = 142.8
4.5 u = 142.8 - 60
4.5 u = 82.8
1 u = 82.8 ÷ 4.5 = 18.4
Amount that Gabby had at first
= 1 u
= $18.40
(b)
Amount that Erika had at first
= 2.5 u + 20
= (2.5 x 18.4) + 20
= 46 + 20
= $66
Answer(s): (a) $18.40; (b) $66