Cody had 90 more pens than Jack. Cody gave 20% of his pens to Jack. Jack in return gave 50% of his pens to Cody. In the end, Jack had 294 less pens than Cody. How many pens did Cody have at first?
| |
Cody |
Jack |
Comparing Cody
and Peter at first |
90 more |
|
| Before |
5 u + 90 |
5 u |
| Change 1 |
- 1 u - 18 |
+ 1 u + 18 |
| After 1 |
4 u + 72 |
6 u + 18 |
| Change 2 |
+ 3 u + 9 |
- 3 u - 9 |
| After 2 |
7 u + 81 |
3 u + 9 |
20% =
20100 =
1520% x 90
=
20100 x 90
= 18
50% x 18
=
50100 x 18
= 9
50% x 6 u
=
50100 x 6 u
= 3 u
Jack had 294 less pens than Cody in the end. If another 294 pens are given to Jack, both will have the same number of pens.
7 u + 81 = 3 u + 9 + 294
7 u - 3 u = 9 + 294 - 81
4 u = 222
1 u = 222 ÷ 4 = 37
Number of Jack's pens at first
= 5 u
= 5 x 37
= 185
Answer: 185
