Simon had 100 more stamps than Carl. Simon gave 25% of his stamps to Carl. Carl in return gave 60% of his stamps to Simon. In the end, Carl had 360 less stamps than Simon. How many stamps did Simon have at first?
| |
Simon |
Carl |
Comparing Simon
and Peter at first |
100 more |
|
| Before |
4 u + 100 |
4 u |
| Change 1 |
- 1 u - 25 |
+ 1 u + 25 |
| After 1 |
3 u + 75 |
5 u + 25 |
| Change 2 |
+ 3 u + 15 |
- 3 u - 15 |
| After 2 |
6 u + 90 |
2 u + 10 |
25% =
25100 =
1425% x 100
=
25100 x 100
= 25
60% x 25
=
60100 x 25
= 15
60% x 5 u
=
60100 x 5 u
= 3 u
Carl had 360 less stamps than Simon in the end. If another 360 stamps are given to Carl, both will have the same number of stamps.
6 u + 90 = 2 u + 10 + 360
6 u - 2 u = 10 + 360 - 90
4 u = 280
1 u = 280 ÷ 4 = 35
Number of Carl's stamps at first
= 4 u
= 4 x 35
= 140
Answer: 140
