Carl had 80 more pens than Luke. Carl gave 25% of his pens to Luke. Luke in return gave 80% of his pens to Carl. In the end, Carl had 150 more pens than Luke. How many pens did Carl have at first?
| |
Carl |
Luke |
Comparing Carl
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
Carl had 150 more pens than Luke in the end. If another 150 pens are given to Luke, both will have the same number of pens.
7 u + 76 = 1 u + 4 + 150
7 u - 1 u = 4 + 150 - 76
3 u = 78
1 u = 78 ÷ 3 = 26
Number of Carl's pens at first
= 4 u + 80
= 4 x 26 + 80
= 104 + 80
= 184
Answer: 184
