The figure, not drawn to scale, is made of two connected cubical tanks, F and G. Tank F is sealed at the top and completely filled to the brim. Tank G is ⁴₅ filled with 131268 mℓ of water. The height of the water level in Tank G is 4 cm higher than that in Tank F. Height of Tank G is 69 cm. Water is then drained from the container and the height of the water level from the base falls to 25 cm.

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

(a)
⁴₅ of Tank G = 131268 mℓ
¹₅ of Tank G = 131268 ÷ 4 = 32817 mℓ
⁵₅ of Tank G = 32817 x 5 = 164085 mℓ

1 ℓ = 1000 mℓ

Capacity of Tank G = 164085 mℓ = 164.085 ℓ

(b)
Fraction of Tank G not filled
= 1 - ⁴₅
= ¹₅

Height of Tank G not filled
= ¹₅ x 69 cm
= 13.8 cm

Height of Tank F
= 69 - 13.8 - 4
= 51.2 cm

Volume of remaining water in Tank F
= 51.2 x 51.2 x 25
= 65536 cm³ 

Volume of remaining water in Tank G
= 69 x 69 x 25
= 119025 cm³ 

Total volume of remaining water in the tank
= 65536 + 119025
= 184561 cm³

1 ℓ = 1000 cm³
184561 cm³ = 184.561 ℓ

Answer(s): (a) 164.085 ℓ; (b) 184.561 ℓ