Mrs Lim gave Barbara and Ivory some money each on Monday. On Tuesday, Barbara gave
13 of the amount she had to Ivory. On Wednesday, Ivory gave
14 of the amount she had to Barbara. In the end, Barbara had $22 and Ivory had $12. How much did Ivory had more than Barbara at first?
|
Barbara |
Ivory |
Total |
Before 1 |
3 u |
? |
$34 |
Change 1 |
- 1 u |
+ 1 u |
|
After 1 |
2 u |
4 p |
$34 |
Before 2 |
$22 - 1 p |
4 p |
$34 |
Change 2 |
+ 1 p |
- 1 p |
|
After 2 |
$22 |
3 p ($12) |
$34 |
Amount that Ivory had in the end = 3 p
3 p = 12
1 p = 12 ÷ 3 = 4
Working backwards.
Amount that Barbara had after giving to Ivory on Tuesday
= 22 - 1 p
= 22 - 4
= $18
2 u = 18
1 u = 18 ÷ 2 = 9
Amount that Barbara had at first
= 3 u
= 3 x 9
= $27
Total amount that Barbara and Ivory had
= 22 + 12
= $34
Amount that Ivory had at first
= 34 - 27
= $7
Amount that Barbara had more than Ivory
= 27 - 7
= $20
Answer(s): $20