There is a cube having sides 5cm.It is painted red on each of its sides. Now if the cube is cut into smaller cubes of side 1cm each(i.e.volume of each cube will be 1*1*1=1 cubic cm)..then how many smaller cubes will remain unpainted??

When a 5cm cube is cut into 1cm cubes, we get 5 × 5 × 5 = 125 total cubes. Only the outer layer gets painted. The inner unpainted portion is a 3cm × 3cm × 3cm cube (since we lose 1cm from each side), giving 3 × 3 × 3 = 27 unpainted cubes. Alternatively, painted cubes = total - inner = 125 - 27 = 98, but the question asks for unpainted ones.