Gwen had 1780 mℓ more tea than Hilda. After Gwen gave Hilda 450 mℓ of tea, the ratio of Gwen's tea to Hilda's tea became 7 : 3. How much tea did Gwen have at first? Give your answer in millilitres.
|
Gwen |
Hilda |
Difference |
Before |
1 u + 1780 |
1 u |
1780 |
Change |
- 450 |
+ 450 |
|
After |
1 u + 1330 |
1 u + 450 |
880 |
Comparing Gwen and Hilda in the end |
7 p |
3 p |
4 p |
Volume of tea that Gwen had in the end
= 1 u + 1780 - 450
= 1 u + 1330
Difference in the volume of tea between Gwen and Hilda in the end
= 7 p - 3 p
= 4 p
4 p = 1330 - 450
4 p = 880
1 p = 880 ÷ 4 = 220
Volume of tea that Gwen had at first
= 7 p + 450
= 7 x 220 + 450
= 1540 + 450
= 1990 mℓ
Answer(s): 1990 mℓ