Rachel had 1700 mℓ more coffee than Risa. After Rachel gave Risa 550 mℓ of coffee, the ratio of Rachel's coffee to Risa's coffee became 5 : 3. How much coffee did Rachel have at first? Give your answer in millilitres.
| |
Rachel |
Risa |
Difference |
| Before |
1 u + 1700 |
1 u |
1700 |
| Change |
- 550 |
+ 550 |
|
| After |
1 u + 1150 |
1 u + 550 |
600 |
Comparing Rachel and
Risa in the end |
5 p |
3 p |
2 p |
Volume of coffee that Rachel had in the end
= 1 u + 1700 - 550
= 1 u + 1150
Difference in the volume of coffee between Rachel and Risa in the end
= 5 p - 3 p
= 2 p
2 p = 1150 - 550
2 p = 600
1 p = 600 ÷ 2 = 300
Volume of coffee that Rachel had at first
= 5 p + 550
= 5 x 300 + 550
= 1500 + 550
= 2050 mℓ
Answer(s): 2050 mℓ
