George had 200 more cards than Tommy. George gave 25% of his cards to Tommy. Tommy in return gave 60% of his cards to George. In the end, George had 610 more cards than Tommy. How many cards did George have at first?
| |
George |
Tommy |
Comparing George
and Peter at first |
200 more |
|
| Before |
4 u + 200 |
4 u |
| Change 1 |
- 1 u - 50 |
+ 1 u + 50 |
| After 1 |
3 u + 150 |
5 u + 50 |
| Change 2 |
+ 3 u + 30 |
- 3 u - 30 |
| After 2 |
6 u + 180 |
2 u + 20 |
25% =
25100 =
1425% x 200
=
25100 x 200
= 50
60% x 50
=
60100 x 50
= 30
60% x 5 u
=
60100 x 5 u
= 3 u
George had 610 more cards than Tommy in the end. If another 610 cards are given to Tommy, both will have the same number of cards.
6 u + 180 = 2 u + 20 + 610
6 u - 2 u = 20 + 610 - 180
18 u = 450
1 u = 450 ÷ 18 = 25
Number of George's cards at first
= 4 u + 200
= 4 x 25 + 200
= 100 + 200
= 300
Answer: 300
