PSLE
Winnie had a bottle of coffee. She drank 540 mℓ of coffee in the afternoon and ³₅ of remaining coffee in the evening. After that, there was ¹₇ a bottle of coffee left. How much of the coffee did she drink in the evening?
Fraction of the remaining coffee left in the end
= 1 - ³₅
= ²₅

The remaining coffee left in the end is equal to ¹₇ of the bottle of coffee.
Make numerators the same.
LCM of 2 and 1 is 2.
 
²₅ of the remaining coffee = ¹₇ of the total coffee
²₅ of the remaining coffee = ²₁₄ of the total coffee

Volume of coffee that she drank in the afternoon
= 14 u - 5 u
= 9 u

9 u = 540

1 u = 540 ÷ 9 = 60

Volume of coffee that she drank in the evening
= 3 u
= 3 x 60
= 180 mℓ

Answer(s): 180 mℓ