Answer:
The height of the block is 2.5 cm
Solution:
Let us assume the height of the block =h
The length of the rectangle l = 12 cm
The width of the rectangle w = 5 cm
The volume of the rectangle

We know the volume of the rectangular block

So,
=\left(\frac{30}{12}\right)
=\left(\frac{5}{2}\right) = 2.5
So, the height is 2.5 cm