Mrs Zhang gave Zoe and Roshel some money each on Tuesday. On Wednesday, Zoe gave
15 of the amount she had to Roshel. On Thursday, Roshel gave
13 of the amount she had to Zoe. In the end, Zoe had $37 and Roshel had $18. How much did Roshel had more than Zoe at first?
| |
Zoe |
Roshel |
Total |
| Before 1 |
5 u |
? |
$55 |
| Change 1 |
- 1 u |
+ 1 u |
|
| After 1 |
4 u |
3 p |
$55 |
| Before 2 |
$37 - 1 p |
3 p |
$55 |
| Change 2 |
+ 1 p |
- 1 p |
|
After 2 |
$37 |
2 p
($18) |
$55 |
Amount that Roshel had in the end = 2 p
2 p = 18
1 p = 18 ÷ 2 = 9
Working backwards.
Amount that Zoe had after giving to Roshel on Wednesday
= 37 - 1 p
= 37 - 9
= $28
4 u = 28
1 u = 28 ÷ 4 = 7
Amount that Zoe had at first
= 5 u
= 5 x 7
= $35
Total amount that Zoe and Roshel had
= 37 + 18
= $55
Amount that Roshel had at first
= 55 - 35
= $20
Amount that Zoe had more than Roshel
= 35 - 20
= $15
Answer(s): $15
