Opal, Risa and Diana had a sum of money. The amount of money Opal had was
23 of the amount of money Risa had. The ratio of the amount of money Risa had to the total amount of money Diana and Risa had was 4: 9. After Diana gave $33 to Risa, she had as much money as Risa. How much more money did Diana have than Opal in the end?
Opal |
Risa |
Diana |
2x4 = 8 u |
3x4 = 12 u |
|
|
4x3 = 12 u |
5x3 = 15 u |
8 u |
12 u |
15 u |
The amount that Risa had is the repeated identity. Make the amount that Risa had the same. LCM of 3 and 4 is 12.
|
Opal |
Risa |
Diana |
Before |
8 u |
12 u |
15 u |
Change |
No change |
+ 33 |
- 33 |
After |
8 u |
12 u + 33 |
15 u - 33 |
The amount that Diana and Risa had in the end is the same.
15 u - 33 = 12 u + 33
15 u - 12 u = 33 + 33
3 u = 66
1 u = 66 ÷ 3 = 22
Amount that Diana had more than Opal in the end
= 15 u - 33 - 8 u
= 7 u - 33
= 7 x 22 - 33
= 154 - 33
= $121
Answer(s): $121