Mrs Yang gave Kathy and Mary some money each on Monday. On Tuesday, Kathy gave
14 of the amount she had to Mary. On Wednesday, Mary gave
13 of the amount she had to Kathy. In the end, Kathy had $39 and Mary had $6. How much did Mary had more than Kathy at first?
| |
Kathy |
Mary |
Total |
| Before 1 |
4 u |
? |
$45 |
| Change 1 |
- 1 u |
+ 1 u |
|
| After 1 |
3 u |
3 p |
$45 |
| Before 2 |
$39 - 1 p |
3 p |
$45 |
| Change 2 |
+ 1 p |
- 1 p |
|
After 2 |
$39 |
2 p
($6) |
$45 |
Amount that Mary had in the end = 2 p
2 p = 6
1 p = 6 ÷ 2 = 3
Working backwards.
Amount that Kathy had after giving to Mary on Tuesday
= 39 - 1 p
= 39 - 3
= $36
3 u = 36
1 u = 36 ÷ 3 = 12
Amount that Kathy had at first
= 4 u
= 4 x 12
= $48
Total amount that Kathy and Mary had
= 39 + 6
= $45
Amount that Mary had at first
= 45 - 48
= $-3
Amount that Kathy had more than Mary
= 48 - -3
= $51
Answer(s): $51
