Esther had 1380 mℓ more orange juice than Tiffany. After Esther gave Tiffany 410 mℓ of orange juice, the ratio of Esther's orange juice to Tiffany's orange juice became 7 : 3. How much orange juice did Esther have at first? Give your answer in millilitres.
| |
Esther |
Tiffany |
Difference |
| Before |
1 u + 1380 |
1 u |
1380 |
| Change |
- 410 |
+ 410 |
|
| After |
1 u + 970 |
1 u + 410 |
560 |
Comparing Esther and
Tiffany in the end |
7 p |
3 p |
4 p |
Volume of orange juice that Esther had in the end
= 1 u + 1380 - 410
= 1 u + 970
Difference in the volume of orange juice between Esther and Tiffany in the end
= 7 p - 3 p
= 4 p
4 p = 970 - 410
4 p = 560
1 p = 560 ÷ 4 = 140
Volume of orange juice that Esther had at first
= 7 p + 410
= 7 x 140 + 410
= 980 + 410
= 1390 mℓ
Answer(s): 1390 mℓ
