PSLE
Shiyun had a bottle of soy milk. She drank 510 mℓ of soy milk in the morning and ²₇ of remaining soy milk in the evening. After that, there was ¹₂ a bottle of soy milk left. How much of the soy milk did she drink in the evening?
Fraction of the remaining soy milk left in the end
= 1 - ²₇
= ⁵₇

The remaining soy milk left in the end is equal to ¹₂ of the bottle of soy milk.
Make numerators the same.
LCM of 5 and 1 is 5.
 
⁵₇ of the remaining soy milk = ¹₂ of the total soy milk
⁵₇ of the remaining soy milk = ⁵₁₀ of the total soy milk

Volume of soy milk that she drank in the morning
= 10 u - 7 u
= 3 u

3 u = 510

1 u = 510 ÷ 3 = 170

Volume of soy milk that she drank in the evening
= 2 u
= 2 x 170
= 340 mℓ

Answer(s): 340 mℓ