Oscar had 160 more pens than Peter. Oscar gave 25% of his pens to Peter. Peter in return gave 80% of his pens to Oscar. In the end, Oscar had 424 more pens than Peter. How many pens did Oscar have at first?
| |
Oscar |
Peter |
Comparing Oscar
and Peter at first |
160 more |
|
| Before |
4 u + 160 |
4 u |
| Change 1 |
- 1 u - 40 |
+ 1 u + 40 |
| After 1 |
3 u + 120 |
5 u + 40 |
| Change 2 |
+ 4 u + 32 |
- 4 u - 32 |
| After 2 |
7 u + 152 |
1 u + 8 |
25% =
25100 =
1425% x 160
=
25100 x 160
= 40
80% x 40
=
80100 x 40
= 32
80% x 5 u
=
80100 x 5 u
= 4 u
Oscar had 424 more pens than Peter in the end. If another 424 pens are given to Peter, both will have the same number of pens.
7 u + 152 = 1 u + 8 + 424
7 u - 1 u = 8 + 424 - 152
7 u = 280
1 u = 280 ÷ 7 = 40
Number of Oscar's pens at first
= 4 u + 160
= 4 x 40 + 160
= 160 + 160
= 320
Answer: 320
