The figure, not drawn to scale, is made of two connected cubical tanks, H and J. Tank H is sealed at the top and completely filled to the brim. Tank J is ²₃ filled with 129520 mℓ of water. The height of the water level in Tank J is 4 cm higher than that in Tank H. Height of Tank J is 69 cm. Water is then drained from the container and the height of the water level from the base falls to 28 cm.

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

(a)
²₃ of Tank J = 129520 mℓ
¹₃ of Tank J = 129520 ÷ 2 = 64760 mℓ
³₃ of Tank J = 64760 x 3 = 194280 mℓ

1 ℓ = 1000 mℓ

Capacity of Tank J = 194280 mℓ = 194.28 ℓ

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

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

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

Volume of remaining water in Tank H
= 42 x 42 x 28
= 49392 cm³ 

Volume of remaining water in Tank J
= 69 x 69 x 28
= 133308 cm³ 

Total volume of remaining water in the tank
= 49392 + 133308
= 182700 cm³

1 ℓ = 1000 cm³
182700 cm³ = 182.7 ℓ

Answer(s): (a) 194.28 ℓ; (b) 182.7 ℓ