David and Vincent had 32 staplers together. David had 8 more staplers than Vincent. Both of them sold some of their staplers. Vincent sold 25% less staplers than what David sold. In the end, Vincent had half as many staplers left as David. How many staplers had David left?
| |
David
(1) |
Vincent
(2) |
Make p the same
(2)x2 = (3) |
Comparing David
and Vincent at first |
8 more |
|
|
| Before |
20 |
12 |
24 |
| Change |
- 4 u |
- 3 u |
- 6 u |
| After |
2 p |
1 p |
2 p |
Number of staplers that Vincent had at first
= (32 - 8) ÷ 2
= 24 ÷ 2
= 12
Number of staplers that David had at first
= 12 + 8
= 20
Number of staplers that Vincent sold in percent
= 100% - 25%
= 75%
75% =
75100 =
34 Make p the same.
(1) = (3)
20 - 4 u = 24 - 6 u
6 u - 4 u = 24 - 20
2 u = 4
1 u = 4 ÷ 2 = 2
Number of staplers that David had left
= 20 - 4 u
= 20 - 4 x 2
= 20 - 8
= 12
Answer(s): 12
