On Thursday, Cathy, Esther, Irene and Nora spent a total of $100. On Friday, Cathy spent twice of what she spent on Thursday, Esther spent the same as what she spent on Thursday, Irene spent $17 less than what she spent on Thursday, and Nora spent $1 more than what she spent on Thursday. All of them spent an equal amount on Friday. How much did Cathy and Nora spend altogether on Thursday?
|
Cathy |
Esther |
Irene |
Nora |
Total |
Before |
1 u |
2 u |
2 u + $17 |
2 u - $1 |
$100 |
Change |
x 2 |
|
- $17 |
+ $1 |
|
After |
2 u |
2 u |
2 u |
2 u |
|
Total amount that the four girls spent on Thursday
= 1 u + 2 u + 2 u + 17 + 2 u - 1
= 7 u + 17 - 1
= 7 u + 16
7 u + 16 = 100
7 u = 100 - 16
7 u = 84
1 u = 84 ÷ 7 = 12
Total amount that Cathy and Nora spent on Thursday
= 1 u + 2 u - 1
= 3 u - 1
= 3 x 12 - 1
= 36 - 1
= $35
Answer(s): $35