Oscar and Zane had the same number of cards at first. After Oscar had bought another 30 cards and Zane had lost 9 of his cards, Oscar had four times as many cards as Zane. How many cards did each of them have at first?
| |
Zane |
Oscar |
| Before |
1 u + 9 |
4 u - 30 |
| Change |
- 9 |
+ 30 |
| After |
1 u |
4 u |
Oscar and Zane had the same number of cards at first.
4 u - 30 = 1 u + 9
4 u - 1 u = 9 + 30
3 u = 39
1 u = 39 ÷ 3 = 13
Number of cards that each of them had at first
= 1 u + 9
= 13 + 9
= 22
Answer(s): 22
