Opal had 1660 mℓ more soy milk than Hazel. After Opal gave Hazel 430 mℓ of soy milk, the ratio of Opal's soy milk to Hazel's soy milk became 7 : 3. How much soy milk did Opal have at first? Give your answer in millilitres.
|
Opal |
Hazel |
Difference |
Before |
1 u + 1660 |
1 u |
1660 |
Change |
- 430 |
+ 430 |
|
After |
1 u + 1230 |
1 u + 430 |
800 |
Comparing Opal and Hazel in the end |
7 p |
3 p |
4 p |
Volume of soy milk that Opal had in the end
= 1 u + 1660 - 430
= 1 u + 1230
Difference in the volume of soy milk between Opal and Hazel in the end
= 7 p - 3 p
= 4 p
4 p = 1230 - 430
4 p = 800
1 p = 800 ÷ 4 = 200
Volume of soy milk that Opal had at first
= 7 p + 430
= 7 x 200 + 430
= 1400 + 430
= 1830 mℓ
Answer(s): 1830 mℓ