The figure is not drawn to scale. B and C are two containers. The base area of B is 12 cm² while the base area of C is 40 cm². Container B and C contained some water and the height of the water level in Container B was 56 cm as shown. Dan then poured some water from Container B into Container C. After that, the height of the water level in both tanks became 29 cm. What was the height of the water level in Container C at first?
Change in the water level of Container B
= 56 - 29
= 27 cm

Volume of water poured in the Container C
= 12 x 27
= 324 cm³ 

Height increase in Container C
= 324 ÷ 40
= 8.1 cm

Original height of the water in Container C
= 29 - 8.1
= 20.9 cm

Answer(s): 20.9 cm