Cathy had 2000 mℓ more tea than Roshel. After Cathy gave Roshel 400 mℓ of tea, the ratio of Cathy's tea to Roshel's tea became 7 : 3. How much tea did Cathy have at first? Give your answer in millilitres.
| |
Cathy |
Roshel |
Difference |
| Before |
1 u + 2000 |
1 u |
2000 |
| Change |
- 400 |
+ 400 |
|
| After |
1 u + 1600 |
1 u + 400 |
1200 |
Comparing Cathy and
Roshel in the end |
7 p |
3 p |
4 p |
Volume of tea that Cathy had in the end
= 1 u + 2000 - 400
= 1 u + 1600
Difference in the volume of tea between Cathy and Roshel in the end
= 7 p - 3 p
= 4 p
4 p = 1600 - 400
4 p = 1200
1 p = 1200 ÷ 4 = 300
Volume of tea that Cathy had at first
= 7 p + 400
= 7 x 300 + 400
= 2100 + 400
= 2500 mℓ
Answer(s): 2500 mℓ
