Andy had 120 more cards than Carl. Andy gave 25% of his cards to Carl. Carl in return gave 60% of his cards to Andy. In the end, Andy had 416 more cards than Carl. How many cards did Andy have at first?
| |
Andy |
Carl |
Comparing Andy
and Peter at first |
120 more |
|
| Before |
4 u + 120 |
4 u |
| Change 1 |
- 1 u - 30 |
+ 1 u + 30 |
| After 1 |
3 u + 90 |
5 u + 30 |
| Change 2 |
+ 3 u + 18 |
- 3 u - 18 |
| After 2 |
6 u + 108 |
2 u + 12 |
25% =
25100 =
1425% x 120
=
25100 x 120
= 30
60% x 30
=
60100 x 30
= 18
60% x 5 u
=
60100 x 5 u
= 3 u
Andy had 416 more cards than Carl in the end. If another 416 cards are given to Carl, both will have the same number of cards.
6 u + 108 = 2 u + 12 + 416
6 u - 2 u = 12 + 416 - 108
10 u = 320
1 u = 320 ÷ 10 = 32
Number of Andy's cards at first
= 4 u + 120
= 4 x 32 + 120
= 128 + 120
= 248
Answer: 248
