On Thursday, Gillian, Roshel, Victoria and Lucy spent a total of $129. On Friday, Gillian spent twice of what she spent on Thursday, Roshel spent the same as what she spent on Thursday, Victoria spent $20 less than what she spent on Thursday, and Lucy spent $11 more than what she spent on Thursday. All of them spent an equal amount on Friday. How much did Gillian and Lucy spend altogether on Thursday?
| |
Gillian |
Roshel |
Victoria |
Lucy |
Total |
| Before |
1 u |
3 u |
3 u + $20 |
3 u - $11 |
$129 |
| Change |
x 3 |
|
- $20 |
+ $11 |
|
| After |
3 u |
3 u |
3 u |
3 u |
|
Total amount that the four girls spent on Thursday
= 1 u + 3 u + 3 u + 20 + 3 u - 11
= 10 u + 20 - 11
= 10 u + 9
10 u + 9 = 129
10 u = 129 - 9
10 u = 120
1 u = 120 ÷ 10 = 12
Total amount that Gillian and Lucy spent on Thursday
= 1 u + 3 u - 11
= 4 u - 11
= 4 x 12 - 11
= 48 - 11
= $37
Answer(s): $37
