Esther had 2360 mℓ more coffee than Kimberly. After Esther gave Kimberly 540 mℓ of coffee, the ratio of Esther's coffee to Kimberly's coffee became 7 : 3. How much coffee did Esther have at first? Give your answer in millilitres.
|
Esther |
Kimberly |
Difference |
Before |
1 u + 2360 |
1 u |
2360 |
Change |
- 540 |
+ 540 |
|
After |
1 u + 1820 |
1 u + 540 |
1280 |
Comparing Esther and Kimberly in the end |
7 p |
3 p |
4 p |
Volume of coffee that Esther had in the end
= 1 u + 2360 - 540
= 1 u + 1820
Difference in the volume of coffee between Esther and Kimberly in the end
= 7 p - 3 p
= 4 p
4 p = 1820 - 540
4 p = 1280
1 p = 1280 ÷ 4 = 320
Volume of coffee that Esther had at first
= 7 p + 540
= 7 x 320 + 540
= 2240 + 540
= 2780 mℓ
Answer(s): 2780 mℓ