The ratio of Gabriel's marbles to Evan's marbles at first was 3 : 7. After Gabriel gave Evan 28 marbles, the ratio of Gabriel's marbles to Evan's marbles is 1 : 3. What was the number of marbles they had in total?
|
Gabriel |
Evan |
Total |
Before |
3x4 = 12 u |
7x4 = 28 u
|
10x4 = 40 u |
Change |
- 28 |
+ 28 |
|
After |
1x10 = 10 u |
3x10 = 30 u |
4x10 = 40 u |
Number of marbles that Gabriel gave Evan
= 12 u - 10 u
= 2 u
2 u = 28
1 u = 28 ÷ 2 = 14
Total number of marbles that they had
= 40 u
= 40 x 14
= 560
Answer(s): 560