Linda had 1520 mℓ more milk than Gillian. After Linda gave Gillian 490 mℓ of milk, the ratio of Linda's milk to Gillian's milk became 7 : 4. How much milk did Linda have at first? Give your answer in millilitres.
|
Linda |
Gillian |
Difference |
Before |
1 u + 1520 |
1 u |
1520 |
Change |
- 490 |
+ 490 |
|
After |
1 u + 1030 |
1 u + 490 |
540 |
Comparing Linda and Gillian in the end |
7 p |
4 p |
3 p |
Volume of milk that Linda had in the end
= 1 u + 1520 - 490
= 1 u + 1030
Difference in the volume of milk between Linda and Gillian in the end
= 7 p - 4 p
= 3 p
3 p = 1030 - 490
3 p = 540
1 p = 540 ÷ 3 = 180
Volume of milk that Linda had at first
= 7 p + 490
= 7 x 180 + 490
= 1260 + 490
= 1750 mℓ
Answer(s): 1750 mℓ