Mrs Tan gave Vanessa and Risa some money each on Monday. On Tuesday, Vanessa gave
15 of the amount she had to Risa. On Wednesday, Risa gave
16 of the amount she had to Vanessa. In the end, Vanessa had $18 and Risa had $10. How much did Risa had more than Vanessa at first?
| |
Vanessa |
Risa |
Total |
| Before 1 |
5 u |
? |
$28 |
| Change 1 |
- 1 u |
+ 1 u |
|
| After 1 |
4 u |
6 p |
$28 |
| Before 2 |
$18 - 1 p |
6 p |
$28 |
| Change 2 |
+ 1 p |
- 1 p |
|
After 2 |
$18 |
5 p
($10) |
$28 |
Amount that Risa had in the end = 5 p
5 p = 10
1 p = 10 ÷ 5 = 2
Working backwards.
Amount that Vanessa had after giving to Risa on Tuesday
= 18 - 1 p
= 18 - 2
= $16
4 u = 16
1 u = 16 ÷ 4 = 4
Amount that Vanessa had at first
= 5 u
= 5 x 4
= $20
Total amount that Vanessa and Risa had
= 18 + 10
= $28
Amount that Risa had at first
= 28 - 20
= $8
Amount that Vanessa had more than Risa
= 20 - 8
= $12
Answer(s): $12
