Sam had 80 more buttons than Owen. Sam gave 25% of his buttons to Owen. Owen in return gave 80% of his buttons to Sam. In the end, Owen had 189 less buttons than Sam. How many buttons did Sam have at first?
| |
Sam |
Owen |
Comparing Sam
and Peter at first |
80 more |
|
| Before |
4 u + 80 |
4 u |
| Change 1 |
- 1 u - 20 |
+ 1 u + 20 |
| After 1 |
3 u + 60 |
5 u + 20 |
| Change 2 |
+ 4 u + 16 |
- 4 u - 16 |
| After 2 |
7 u + 76 |
1 u + 4 |
25% =
25100 =
1425% x 80
=
25100 x 80
= 20
80% x 20
=
80100 x 20
= 16
80% x 5 u
=
80100 x 5 u
= 4 u
Owen had 189 less buttons than Sam in the end. If another 189 buttons are given to Owen, both will have the same number of buttons.
7 u + 76 = 1 u + 4 + 189
7 u - 1 u = 4 + 189 - 76
6 u = 117
1 u = 117 ÷ 6 = 39
Number of Owen's buttons at first
= 4 u
= 4 x 39
= 156
Answer: 156
