### Solution:

We know that a cuboid is a three-dimensional object with six rectangular faces connected by 8 vertices. It has three different types of sides called length, width parallel to the ground, and height perpendicular to the ground denoted as a and . The size of the space contained in a three-dimensional object is measured by a quantity called volume. The amount of space occupied by a cuboid is the product of length, width, and height. Mathematically, the volume V of a cuboid isIf the length, width and height are equal, we call the cuboid a cube. The amount of water contained in the space of a 1 cm cube is called 1 milliliter (ml). So 1ml of water is contained in space. So now we will find out how much water is contained in a cube with a side of 1 meter (m).

The size of the space contained in a 1 m cube is

$\n \n V=1m\xd71m\xd71m=100cm\xd7100cm\xd7100cm=100000c\n m\n 3\n \n \n $

We know that 1000ml=1litre. $\n \n 1c\n m\n 3\n \n \n $ of space contains $\n \n 1ml=\n 1\n \n 1000\n \n litre\n $ of water. So of $\n \n 1000000c\n m\n 3\n \n \n $ space will be contained $\n \n 1000000ml=1000000\xd7\n 1\n \n 1000\n \n =1000\n $ litre of water.

We find that a cube with side 1m or $\n \n \n \n 1m\n 3\n \n \n $ of space will contain 1000 litre of water. We are given the question that the water tank has length $\n \n l=4m\n $ , breadth $\n \n b=1.5m\n $ , height $\n \n h=1m\n $ . It is in cuboid shape.

The volume of the cuboid shaped water tank is

$\n \n V=lbh=4m\xd71.5m\xd71m=6\n m\n 3\n \n \n $

The total amount of water above water tank contains is

$\n \n \n V\n l\n \n =6\xd71000litre=6000litre\n $

The amount of water that is extracted in one time by the bucket is $\n \n \n V\n b\n \n =8\n $ litre. The number of times required to empty the water tank is

$\n \n \n \n \n V\n l\n \n \n \n \n V\n b\n \n \n \n =\n \n 6000\n 8\n \n =750\n $

So, the correct Ans is Option 2.