The figure, not drawn to scale, is made of two connected cubical tanks, C and D. Tank C is sealed at the top and completely filled to the brim. Tank D is ²₃ filled with 133382 mℓ of water. The height of the water level in Tank D is 4 cm higher than that in Tank C. Height of Tank D is 69 cm. Water is then drained from the container and the height of the water level from the base falls to 26 cm.

1. What is the capacity of Tank D in litres?
2. What is the volume of water in the tank now in litres?

(a)
²₃ of Tank D = 133382 mℓ
¹₃ of Tank D = 133382 ÷ 2 = 66691 mℓ
³₃ of Tank D = 66691 x 3 = 200073 mℓ

1 ℓ = 1000 mℓ

Capacity of Tank D = 200073 mℓ = 200.073 ℓ

(b)
Fraction of Tank D not filled
= 1 - ²₃
= ¹₃

Height of Tank D not filled
= ¹₃ x 69 cm
= 23 cm

Height of Tank C
= 69 - 23 - 4
= 42 cm

Volume of remaining water in Tank C
= 42 x 42 x 26
= 45864 cm³ 

Volume of remaining water in Tank D
= 69 x 69 x 26
= 123786 cm³ 

Total volume of remaining water in the tank
= 45864 + 123786
= 169650 cm³

1 ℓ = 1000 cm³
169650 cm³ = 169.65 ℓ

Answer(s): (a) 200.073 ℓ; (b) 169.65 ℓ