What will be the volume of water that a tank of dimensions: $10m\times 5m\times 20m$ can store?

We are given a tank of dimensions: $10m\times 5m\times 20m$

Now, we know that the formula for calculating the volume for a cuboid (tank is a cuboid) is as follows:

$Volume=l\times b\times h$

Now, substituting the dimensions in the expression, we get:

$Volume=10m\times 5m\times 20m$

Simplifying this, we get:

$Volume=1000m^3$

The volume of the water that the tank can store is found to be option (D) $1000m^3$.