David and Ben had $756 altogether. Ben gave
25 of his money to David. After that, David gave
35 of his money to Ben. In the end, David had
16 of the total sum of money. How much did David have at first?
| |
Ben |
David |
Total |
| Before 1 |
5 p |
? |
$756 |
| Change 1 |
- 2 p |
+ 2 p |
|
| After 1 |
3 p |
5 u |
|
| Before 2 |
3 p |
5x1 =
5 u |
$756 |
| Change 2 |
+ 3x1 =
+ 3 u |
- 3x1 =
- 3 u |
|
| After 2 |
|
2x1 =
2 u |
$756 |
Comparing between
Ben and David
in the end |
5x2 =
10 u |
1x2 =
2 u |
$756 |
The amount that David had in the end is the repeated. Make the amount that David had in the end the same. LCM of 2 and 1 is 2.
12 u = 756
1 u = 756 ÷ 12 = 63
5 u = 5 x 63 = 315
3 p = 756 - 315 = 441
1 p = 441 ÷ 3 = 147
Amount that Ben had at first
= 5 p
= 5 x 147
= $735
Amount that David had at first
= 756 - 735
= $21
Answer(s): $21
