Diana had 1970 mℓ more orange juice than Abi. After Diana gave Abi 490 mℓ of orange juice, the ratio of Diana's orange juice to Abi's orange juice became 7 : 4. How much orange juice did Diana have at first? Give your answer in millilitres.
|
Diana |
Abi |
Difference |
Before |
1 u + 1970 |
1 u |
1970 |
Change |
- 490 |
+ 490 |
|
After |
1 u + 1480 |
1 u + 490 |
990 |
Comparing Diana and Abi in the end |
7 p |
4 p |
3 p |
Volume of orange juice that Diana had in the end
= 1 u + 1970 - 490
= 1 u + 1480
Difference in the volume of orange juice between Diana and Abi in the end
= 7 p - 4 p
= 3 p
3 p = 1480 - 490
3 p = 990
1 p = 990 ÷ 3 = 330
Volume of orange juice that Diana had at first
= 7 p + 490
= 7 x 330 + 490
= 2310 + 490
= 2800 mℓ
Answer(s): 2800 mℓ