The ratio of Sebastian's cards to Raeann's cards at first was 3 : 7. After Sebastian gave Raeann 90 cards, the ratio of Sebastian's cards to Raeann's cards is 1 : 3. What was the number of cards they had in total?
| |
Sebastian |
Raeann |
Total |
| Before |
3x4 =
12 u |
7x4 =
28 u
|
10x4 =
40 u |
| Change |
- 90 |
+ 90 |
|
| After |
1x10 =
10 u |
3x10 =
30 u |
4x10 =
40 u |
Number of cards that Sebastian gave Raeann
= 12 u - 10 u
= 2 u
2 u = 90
1 u = 90 ÷ 2 = 45
Total number of cards that they had
= 40 u
= 40 x 45
= 1800
Answer(s): 1800
