The ratio of Leah's buttons to Riordan's buttons at first was 3 : 5. After Leah gave Riordan 100 buttons, the ratio of Leah's buttons to Riordan's buttons is 1 : 3. What was the number of buttons they had in all?
| |
Leah |
Riordan |
Total |
| Before |
3x4 =
12 u |
5x4 =
20 u
|
8x4 =
32 u |
| Change |
- 100 |
+ 100 |
|
| After |
1x8 =
8 u |
3x8 =
24 u |
4x8 =
32 u |
Number of buttons that Leah gave Riordan
= 12 u - 8 u
= 4 u
4 u = 100
1 u = 100 ÷ 4 = 25
Total number of buttons that they had
= 32 u
= 32 x 25
= 800
Answer(s): 800
