On Wednesday, Abi, Xuan, Shiyun and Tiffany spent a total of $107. On Thursday, Abi spent twice of what she spent on Wednesday, Xuan spent the same as what she spent on Wednesday, Shiyun spent $18 less than what she spent on Wednesday, and Tiffany spent $11 more than what she spent on Wednesday. All of them spent an equal amount on Thursday. How much did Abi and Tiffany spend altogether on Wednesday?
| |
Abi |
Xuan |
Shiyun |
Tiffany |
Total |
| Before |
1 u |
3 u |
3 u + $18 |
3 u - $11 |
$107 |
| Change |
x 3 |
|
- $18 |
+ $11 |
|
| After |
3 u |
3 u |
3 u |
3 u |
|
Total amount that the four girls spent on Wednesday
= 1 u + 3 u + 3 u + 18 + 3 u - 11
= 10 u + 18 - 11
= 10 u + 7
10 u + 7 = 107
10 u = 107 - 7
10 u = 100
1 u = 100 ÷ 10 = 10
Total amount that Abi and Tiffany spent on Wednesday
= 1 u + 3 u - 11
= 4 u - 11
= 4 x 10 - 11
= 40 - 11
= $29
Answer(s): $29
