a) Volume = length × width × height
Volume = 6 × 6 × 7
Volume = 252
b) You have to subtract the volume of the water with the stone and the volume of the water without the stone.
Volume = 6 × 6 × 9
= 36 × 9
= 324
324 - 252 = 72.
The volume of the stone is 72 cm^3.