On Thursday, Sabrina, Olivia, Shiyun and Diana spent a total of $134. On Friday, Sabrina spent twice of what she spent on Thursday, Olivia spent the same as what she spent on Thursday, Shiyun spent $15 less than what she spent on Thursday, and Diana spent $7 more than what she spent on Thursday. All of them spent an equal amount on Friday. How much did Sabrina and Diana spend altogether on Thursday?
|
Sabrina |
Olivia |
Shiyun |
Diana |
Total |
Before |
1 u |
2 u |
2 u + $15 |
2 u - $7 |
$134 |
Change |
x 2 |
|
- $15 |
+ $7 |
|
After |
2 u |
2 u |
2 u |
2 u |
|
Total amount that the four girls spent on Thursday
= 1 u + 2 u + 2 u + 15 + 2 u - 7
= 7 u + 15 - 7
= 7 u + 8
7 u + 8 = 134
7 u = 134 - 8
7 u = 126
1 u = 126 ÷ 7 = 18
Total amount that Sabrina and Diana spent on Thursday
= 1 u + 2 u - 7
= 3 u - 7
= 3 x 18 - 7
= 54 - 7
= $47
Answer(s): $47