Ian had
29 as many cards as Shiyun. After Ian bought another 113 cards, he had 20 less cards than Shiyun. How many cards did Ian have at first?
| |
Ian |
Shiyun |
| Before |
2 u |
9 u |
| Change |
+ 113 |
|
| After |
2 u + 113 |
9 u |
Shiyun had 20 more cards than Ian in the end. So, if Ian had another 20 cards, he would have the same number of cards as Shiyun.
9 u = 2 u + 113 + 20
9 u - 2 u = 113 + 20
7 u = 133
1 u = 133 ÷ 7 = 19
Number of cards that Ian had at first
= 2 u
= 2 x 19
= 38
Answer: 38
