Wendy had 1820 mℓ more milk than Kimberly. After Wendy gave Kimberly 450 mℓ of milk, the ratio of Wendy's milk to Kimberly's milk became 7 : 3. How much milk did Wendy have at first? Give your answer in millilitres.
|
Wendy |
Kimberly |
Difference |
Before |
1 u + 1820 |
1 u |
1820 |
Change |
- 450 |
+ 450 |
|
After |
1 u + 1370 |
1 u + 450 |
920 |
Comparing Wendy and Kimberly in the end |
7 p |
3 p |
4 p |
Volume of milk that Wendy had in the end
= 1 u + 1820 - 450
= 1 u + 1370
Difference in the volume of milk between Wendy and Kimberly in the end
= 7 p - 3 p
= 4 p
4 p = 1370 - 450
4 p = 920
1 p = 920 ÷ 4 = 230
Volume of milk that Wendy had at first
= 7 p + 450
= 7 x 230 + 450
= 1610 + 450
= 2060 mℓ
Answer(s): 2060 mℓ