PSLE
Yen had a bottle of soy milk. She drank 1200 mℓ of soy milk in the afternoon and ³₅ of remaining soy milk at night. After that, there was ¹₁₀ a bottle of soy milk left. How much of the soy milk did she drink at night?
Fraction of the remaining soy milk left in the end
= 1 - ³₅
= ²₅

The remaining soy milk left in the end is equal to ¹₁₀ of the bottle of soy milk.
Make numerators the same.
LCM of 2 and 1 is 2.
 
²₅ of the remaining soy milk = ¹₁₀ of the total soy milk
²₅ of the remaining soy milk = ²₂₀ of the total soy milk

Volume of soy milk that she drank in the afternoon
= 20 u - 5 u
= 15 u

15 u = 1200

1 u = 1200 ÷ 15 = 80

Volume of soy milk that she drank at night
= 3 u
= 3 x 80
= 240 mℓ

Answer(s): 240 mℓ