Jack had 60 more erasers than Cole. Jack gave 20% of his erasers to Cole. Cole in return gave 50% of his erasers to Jack. In the end, Jack had 156 more erasers than Cole. How many erasers did Jack have at first?
| |
Jack |
Cole |
Comparing Jack
and Peter at first |
60 more |
|
| Before |
5 u + 60 |
5 u |
| Change 1 |
- 1 u - 12 |
+ 1 u + 12 |
| After 1 |
4 u + 48 |
6 u + 12 |
| Change 2 |
+ 3 u + 6 |
- 3 u - 6 |
| After 2 |
7 u + 54 |
3 u + 6 |
20% =
20100 =
1520% x 60
=
20100 x 60
= 12
50% x 12
=
50100 x 12
= 6
50% x 6 u
=
50100 x 6 u
= 3 u
Jack had 156 more erasers than Cole in the end. If another 156 erasers are given to Cole, both will have the same number of erasers.
7 u + 54 = 3 u + 6 + 156
7 u - 3 u = 6 + 156 - 54
3 u = 108
1 u = 108 ÷ 3 = 36
Number of Jack's erasers at first
= 5 u + 60
= 5 x 36 + 60
= 180 + 60
= 240
Answer: 240
