David and Sam had $1008 altogether. Sam gave
25 of his money to David. After that, David gave
35 of his money to Sam. In the end, David had
16 of the total sum of money. How much did David have at first?
| |
Sam |
David |
Total |
| Before 1 |
5 p |
? |
$1008 |
| Change 1 |
- 2 p |
+ 2 p |
|
| After 1 |
3 p |
5 u |
|
| Before 2 |
3 p |
5x1 =
5 u |
$1008 |
| Change 2 |
+ 3x1 =
+ 3 u |
- 3x1 =
- 3 u |
|
| After 2 |
|
2x1 =
2 u |
$1008 |
Comparing between
Sam and David
in the end |
5x2 =
10 u |
1x2 =
2 u |
$1008 |
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 = 1008
1 u = 1008 ÷ 12 = 84
5 u = 5 x 84 = 420
3 p = 1008 - 420 = 588
1 p = 588 ÷ 3 = 196
Amount that Sam had at first
= 5 p
= 5 x 196
= $980
Amount that David had at first
= 1008 - 980
= $28
Answer(s): $28
