Cody had 130 more cards than Tommy. Cody gave 20% of his cards to Tommy. Tommy in return gave 50% of his cards to Cody. In the end, Cody had 394 more cards than Tommy. How many cards did Cody have at first?
| |
Cody |
Tommy |
Comparing Cody
and Peter at first |
130 more |
|
| Before |
5 u + 130 |
5 u |
| Change 1 |
- 1 u - 26 |
+ 1 u + 26 |
| After 1 |
4 u + 104 |
6 u + 26 |
| Change 2 |
+ 3 u + 13 |
- 3 u - 13 |
| After 2 |
7 u + 117 |
3 u + 13 |
20% =
20100 =
1520% x 130
=
20100 x 130
= 26
50% x 26
=
50100 x 26
= 13
50% x 6 u
=
50100 x 6 u
= 3 u
Cody had 394 more cards than Tommy in the end. If another 394 cards are given to Tommy, both will have the same number of cards.
7 u + 117 = 3 u + 13 + 394
7 u - 3 u = 13 + 394 - 117
10 u = 290
1 u = 290 ÷ 10 = 29
Number of Cody's cards at first
= 5 u + 130
= 5 x 29 + 130
= 145 + 130
= 275
Answer: 275
