Mrs Chau gave Zara and Erika some money each on Monday. On Tuesday, Zara gave
13 of the amount she had to Erika. On Wednesday, Erika gave
15 of the amount she had to Zara. In the end, Zara had $29 and Erika had $20. How much did Erika had more than Zara at first?
| |
Zara |
Erika |
Total |
| Before 1 |
3 u |
? |
$49 |
| Change 1 |
- 1 u |
+ 1 u |
|
| After 1 |
2 u |
5 p |
$49 |
| Before 2 |
$29 - 1 p |
5 p |
$49 |
| Change 2 |
+ 1 p |
- 1 p |
|
After 2 |
$29 |
4 p
($20) |
$49 |
Amount that Erika had in the end = 4 p
4 p = 20
1 p = 20 ÷ 4 = 5
Working backwards.
Amount that Zara had after giving to Erika on Tuesday
= 29 - 1 p
= 29 - 5
= $24
2 u = 24
1 u = 24 ÷ 2 = 12
Amount that Zara had at first
= 3 u
= 3 x 12
= $36
Total amount that Zara and Erika had
= 29 + 20
= $49
Amount that Erika had at first
= 49 - 36
= $13
Amount that Zara had more than Erika
= 36 - 13
= $23
Answer(s): $23
