Betty had 1820 mℓ more tea than Min. After Betty gave Min 470 mℓ of tea, the ratio of Betty's tea to Min's tea became 7 : 3. How much tea did Betty have at first? Give your answer in millilitres.
|
Betty |
Min |
Difference |
Before |
1 u + 1820 |
1 u |
1820 |
Change |
- 470 |
+ 470 |
|
After |
1 u + 1350 |
1 u + 470 |
880 |
Comparing Betty and Min in the end |
7 p |
3 p |
4 p |
Volume of tea that Betty had in the end
= 1 u + 1820 - 470
= 1 u + 1350
Difference in the volume of tea between Betty and Min in the end
= 7 p - 3 p
= 4 p
4 p = 1350 - 470
4 p = 880
1 p = 880 ÷ 4 = 220
Volume of tea that Betty had at first
= 7 p + 470
= 7 x 220 + 470
= 1540 + 470
= 2010 mℓ
Answer(s): 2010 mℓ