On Monday, Lucy, Shannon, Shiyun and Emma spent a total of $137. On Tuesday, Lucy spent twice of what she spent on Monday, Shannon spent the same as what she spent on Monday, Shiyun spent $8 less than what she spent on Monday, and Emma spent $1 more than what she spent on Monday. All of them spent an equal amount on Tuesday. How much did Lucy and Emma spend altogether on Monday?
| |
Lucy |
Shannon |
Shiyun |
Emma |
Total |
| Before |
1 u |
3 u |
3 u + $8 |
3 u - $1 |
$137 |
| Change |
x 3 |
|
- $8 |
+ $1 |
|
| After |
3 u |
3 u |
3 u |
3 u |
|
Total amount that the four girls spent on Monday
= 1 u + 3 u + 3 u + 8 + 3 u - 1
= 10 u + 8 - 1
= 10 u + 7
10 u + 7 = 137
10 u = 137 - 7
10 u = 130
1 u = 130 ÷ 10 = 13
Total amount that Lucy and Emma spent on Monday
= 1 u + 3 u - 1
= 4 u - 1
= 4 x 13 - 1
= 52 - 1
= $51
Answer(s): $51
