Billy and Ian had the same number of cards at first. After Billy had bought another 35 cards and Ian had lost 9 of his cards, Billy had thrice as many cards as Ian. How many cards did each of them have at first?
| |
Ian |
Billy |
| Before |
1 u + 9 |
3 u - 35 |
| Change |
- 9 |
+ 35 |
| After |
1 u |
3 u |
Billy and Ian had the same number of cards at first.
3 u - 35 = 1 u + 9
3 u - 1 u = 9 + 35
2 u = 44
1 u = 44 ÷ 2 = 22
Number of cards that each of them had at first
= 1 u + 9
= 22 + 9
= 31
Answer(s): 31
