Tammy had 1900 mℓ more milk than Cathy. After Tammy gave Cathy 440 mℓ of milk, the ratio of Tammy's milk to Cathy's milk became 5 : 2. How much milk did Tammy have at first? Give your answer in millilitres.
|
Tammy |
Cathy |
Difference |
Before |
1 u + 1900 |
1 u |
1900 |
Change |
- 440 |
+ 440 |
|
After |
1 u + 1460 |
1 u + 440 |
1020 |
Comparing Tammy and Cathy in the end |
5 p |
2 p |
3 p |
Volume of milk that Tammy had in the end
= 1 u + 1900 - 440
= 1 u + 1460
Difference in the volume of milk between Tammy and Cathy in the end
= 5 p - 2 p
= 3 p
3 p = 1460 - 440
3 p = 1020
1 p = 1020 ÷ 3 = 340
Volume of milk that Tammy had at first
= 5 p + 440
= 5 x 340 + 440
= 1700 + 440
= 2140 mℓ
Answer(s): 2140 mℓ