Length of tank = 2.5 m
Breadth of tank = 2 m
Height of tank = 3 m
The volume of water in the tank will be equal to the volume of tank.
Since, volume of a cuboid = length × breadth × height
⇒ Volume of tank = 2.5 m × 2 m × 3 m = 15 m3
Thus, the tank can hold 15 cubic metres of water.