If Mark gives Kathy $3, he will have the same amount of money as her. If Kathy gives Mark $3, Mark will have four times as much money as her. How much money does Mark have?
| |
Case 1 |
Case 2 |
| |
Mark |
Kathy |
Mark |
Kathy |
| Before |
5 u + 3 |
5 u - 3 |
2 u - 3 |
8 u + 3 |
| Change |
- 3 |
+ 3 |
+ 3 |
- 3 |
| After |
1x5 =
5 u |
1x5 =
5 u |
1x2 =
2 u |
4x2 =
8 u |
The total amount in both scenarios is the same. Make the total amount the same in bothe cases. LCM of 2 and 5 is 10.
In both case, Mark had the same amount at first.
5 u + 3 = 2 u - 3
5 u - 2 u = 3 + 3
3 u = 6
1 u = 6 ÷ 3 = 2
Amount that Mark has
= 5 u + 3
= 5 x 2 + 3
= $13
Answer(s): $13
