The figure, not drawn to scale, is made of two connected cubical tanks, T and U. Tank T is sealed at the top and completely filled to the brim. Tank U is ³₅ filled with 130467 mℓ of water. The height of the water level in Tank U is 2 cm higher than that in Tank T. Height of Tank U is 65 cm. Water is then drained from the container and the height of the water level from the base falls to 21 cm.

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

(a)
³₅ of Tank U = 130467 mℓ
¹₅ of Tank U = 130467 ÷ 3 = 43489 mℓ
⁵₅ of Tank U = 43489 x 5 = 217445 mℓ

1 ℓ = 1000 mℓ

Capacity of Tank U = 217445 mℓ = 217.445 ℓ

(b)
Fraction of Tank U not filled
= 1 - ³₅
= ²₅

Height of Tank U not filled
= ²₅ x 65 cm
= 26 cm

Height of Tank T
= 65 - 26 - 2
= 37 cm

Volume of remaining water in Tank T
= 37 x 37 x 21
= 28749 cm³ 

Volume of remaining water in Tank U
= 65 x 65 x 21
= 88725 cm³ 

Total volume of remaining water in the tank
= 28749 + 88725
= 117474 cm³

1 ℓ = 1000 cm³
117474 cm³ = 117.474 ℓ

Answer(s): (a) 217.445 ℓ; (b) 117.474 ℓ