Mrs Tan gave Lynn and Shannon some money each on Monday. On Tuesday, Lynn gave
13 of the amount she had to Shannon. On Wednesday, Shannon gave
15 of the amount she had to Lynn. In the end, Lynn had $21 and Shannon had $20. How much did Shannon had more than Lynn at first?
| |
Lynn |
Shannon |
Total |
| Before 1 |
3 u |
? |
$41 |
| Change 1 |
- 1 u |
+ 1 u |
|
| After 1 |
2 u |
5 p |
$41 |
| Before 2 |
$21 - 1 p |
5 p |
$41 |
| Change 2 |
+ 1 p |
- 1 p |
|
After 2 |
$21 |
4 p
($20) |
$41 |
Amount that Shannon had in the end = 4 p
4 p = 20
1 p = 20 ÷ 4 = 5
Working backwards.
Amount that Lynn had after giving to Shannon on Tuesday
= 21 - 1 p
= 21 - 5
= $16
2 u = 16
1 u = 16 ÷ 2 = 8
Amount that Lynn had at first
= 3 u
= 3 x 8
= $24
Total amount that Lynn and Shannon had
= 21 + 20
= $41
Amount that Shannon had at first
= 41 - 24
= $17
Amount that Lynn had more than Shannon
= 24 - 17
= $7
Answer(s): $7
