Eric had 180 more erasers than Ian. Eric gave 25% of his erasers to Ian. Ian in return gave 80% of his erasers to Eric. In the end, Eric had 346 more erasers than Ian. How many erasers did Eric have at first?
| |
Eric |
Ian |
Comparing Eric
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
Eric had 346 more erasers than Ian in the end. If another 346 erasers are given to Ian, both will have the same number of erasers.
7 u + 171 = 1 u + 9 + 346
7 u - 1 u = 9 + 346 - 171
8 u = 184
1 u = 184 ÷ 8 = 23
Number of Eric's erasers at first
= 4 u + 180
= 4 x 23 + 180
= 92 + 180
= 272
Answer: 272
