Oscar had 180 more erasers than Simon. Oscar gave 25% of his erasers to Simon. Simon in return gave 80% of his erasers to Oscar. In the end, Oscar had 426 more erasers than Simon. How many erasers did Oscar have at first?
| |
Oscar |
Simon |
Comparing Oscar
and Peter at first |
180 more |
|
| Before |
4 u + 180 |
4 u |
| Change 1 |
- 1 u - 45 |
+ 1 u + 45 |
| After 1 |
3 u + 135 |
5 u + 45 |
| Change 2 |
+ 4 u + 36 |
- 4 u - 36 |
| After 2 |
7 u + 171 |
1 u + 9 |
25% =
25100 =
1425% x 180
=
25100 x 180
= 45
80% x 45
=
80100 x 45
= 36
80% x 5 u
=
80100 x 5 u
= 4 u
Oscar had 426 more erasers than Simon in the end. If another 426 erasers are given to Simon, both will have the same number of erasers.
7 u + 171 = 1 u + 9 + 426
7 u - 1 u = 9 + 426 - 171
8 u = 264
1 u = 264 ÷ 8 = 33
Number of Oscar's erasers at first
= 4 u + 180
= 4 x 33 + 180
= 132 + 180
= 312
Answer: 312
