In the diagram not drawn to scale, Tank X and Tank Y each has a button that, when pressed, will cause the water to flow out if the water level is higher than the hole. Tank X measures 126 cm by 54 cm by 140 cm. Tank Y measures 56 cm by 29 cm by 60 cm. Tank Z is 70 cm by 23 cm by 23 cm. Both holes are located at a height of 15 cm from the top of their respective containers. When Tank X is completely filled with water and both buttons are pressed, what will be the final water level in Tank Z?
Volume of Tank X to pour into Tank Y
= 126 x 54 x 15
= 102060 cm³

Volume of the Tank Y that can be filled before overflow
= 56 x 29 x (60 - 15)
= 73080 cm³ 

Volume of water in Tank Z
= 102060 - 73080
= 28980 cm³ 

Base area of Tank Z
= 70 x 23
= 1610 cm² 

Final height of Tank Z
= 28980 ÷ 1610
= 18 cm

Answer(s): 18 cm