Simon had 80 more buttons than Harry. Simon gave 20% of his buttons to Harry. Harry in return gave 50% of his buttons to Simon. In the end, Simon had 189 more buttons than Harry. How many buttons did Simon have at first?
| |
Simon |
Harry |
Comparing Simon
and Peter at first |
80 more |
|
| Before |
5 u + 80 |
5 u |
| Change 1 |
- 1 u - 16 |
+ 1 u + 16 |
| After 1 |
4 u + 64 |
6 u + 16 |
| Change 2 |
+ 3 u + 8 |
- 3 u - 8 |
| After 2 |
7 u + 72 |
3 u + 8 |
20% =
20100 =
1520% x 80
=
20100 x 80
= 16
50% x 16
=
50100 x 16
= 8
50% x 6 u
=
50100 x 6 u
= 3 u
Simon had 189 more buttons than Harry in the end. If another 189 buttons are given to Harry, both will have the same number of buttons.
7 u + 72 = 3 u + 8 + 189
7 u - 3 u = 8 + 189 - 72
5 u = 125
1 u = 125 ÷ 5 = 25
Number of Simon's buttons at first
= 5 u + 80
= 5 x 25 + 80
= 125 + 80
= 205
Answer: 205
