Pamela had 1740 mℓ more tea than Cathy. After Pamela gave Cathy 470 mℓ of tea, the ratio of Pamela's tea to Cathy's tea became 7 : 3. How much tea did Pamela have at first? Give your answer in millilitres.
|
Pamela |
Cathy |
Difference |
Before |
1 u + 1740 |
1 u |
1740 |
Change |
- 470 |
+ 470 |
|
After |
1 u + 1270 |
1 u + 470 |
800 |
Comparing Pamela and Cathy in the end |
7 p |
3 p |
4 p |
Volume of tea that Pamela had in the end
= 1 u + 1740 - 470
= 1 u + 1270
Difference in the volume of tea between Pamela and Cathy in the end
= 7 p - 3 p
= 4 p
4 p = 1270 - 470
4 p = 800
1 p = 800 ÷ 4 = 200
Volume of tea that Pamela had at first
= 7 p + 470
= 7 x 200 + 470
= 1400 + 470
= 1870 mℓ
Answer(s): 1870 mℓ