Anna had 1880 mℓ more soy milk than Gem. After Anna gave Gem 420 mℓ of soy milk, the ratio of Anna's soy milk to Gem's soy milk became 7 : 3. How much soy milk did Anna have at first? Give your answer in millilitres.
|
Anna |
Gem |
Difference |
Before |
1 u + 1880 |
1 u |
1880 |
Change |
- 420 |
+ 420 |
|
After |
1 u + 1460 |
1 u + 420 |
1040 |
Comparing Anna and Gem in the end |
7 p |
3 p |
4 p |
Volume of soy milk that Anna had in the end
= 1 u + 1880 - 420
= 1 u + 1460
Difference in the volume of soy milk between Anna and Gem in the end
= 7 p - 3 p
= 4 p
4 p = 1460 - 420
4 p = 1040
1 p = 1040 ÷ 4 = 260
Volume of soy milk that Anna had at first
= 7 p + 420
= 7 x 260 + 420
= 1820 + 420
= 2240 mℓ
Answer(s): 2240 mℓ