A cylindrical dispenser of capacity 6.4 ℓ was filled with mangosteen juice to its brim. The mangosteen juice in the dispenser was then dispensed into a cubical container of sides 20 cm, through a tap flowing at a rate of 230 mℓ /min. After 24 min, the tap was turned off and the container was ³₄ full.

1. What percentage of the mangosteen juice in the cylindrical dispenser was left? Round off your answer to the nearest 2 decimal places.
2. How many litres of mangosteen juice were there in the container at first? (1 ℓ = 1000 cm³)

(a)
Volume of mangosteen juice that was dispensed
= 230 x 24
= 5520 mℓ

1 ℓ = 1000 mℓ
5.52 ℓ = 5520 mℓ

Volume of mangosteen juice Left in the dispenser
= 6.4 - 5.52
= 0.88 ℓ

Percentage of mangosteen juice Left in the dispenser
= 0.88 ÷ 6.4 x 100
= 13.75%
≈ 13.75% (to 2 decimal places)

(b)
Amount of mangosteen juice in the container in the end
= ³₄ x 20 x 20 x 20
= 6000 cm³

Amount of mangosteen juice in the container at first
= 6000 - 5520
= 480 cm³

1000 cm³ = 1  ℓ
480 cm³ = 0.48 ℓ

Answer(s): (a) 13.75%; (b) 0.48 ℓ