The volume would be 80 cubic metres. Think about the three different dimensions for the small room as x,y and z. Therefore the volume is x*y*z= xyz. Now for the bigger room, the dimensions would be 2x,2y and 2z. Therefore, its volume would be 2x*2y*2z= 8xyz. Since xyz (volume of the smaller room)= 10 cubic metres, the bigger room's volume will be 8*10= 80 cubic metres.