Oliver had 190 more stamps than Daniel. Oliver gave 20% of his stamps to Daniel. Daniel in return gave 50% of his stamps to Oliver. In the end, Daniel had 728 less stamps than Oliver. How many stamps did Oliver have at first?
| |
Oliver |
Daniel |
Comparing Oliver
and Peter at first |
190 more |
|
| Before |
5 u + 190 |
5 u |
| Change 1 |
- 1 u - 38 |
+ 1 u + 38 |
| After 1 |
4 u + 152 |
6 u + 38 |
| Change 2 |
+ 3 u + 19 |
- 3 u - 19 |
| After 2 |
7 u + 171 |
3 u + 19 |
20% =
20100 =
1520% x 190
=
20100 x 190
= 38
50% x 38
=
50100 x 38
= 19
50% x 6 u
=
50100 x 6 u
= 3 u
Daniel had 728 less stamps than Oliver in the end. If another 728 stamps are given to Daniel, both will have the same number of stamps.
7 u + 171 = 3 u + 19 + 728
7 u - 3 u = 19 + 728 - 171
4 u = 576
1 u = 576 ÷ 4 = 36
Number of Daniel's stamps at first
= 5 u
= 5 x 36
= 180
Answer: 180
