Three different positions of a dice are shown below. Which number appears on the face opposite the number 6 ?

Solution

As per the diagram, we can see that,
face 3 and 4 are adjacent,
face 3 and 5 are adjacent,
and adjacent 4 and 5 are adjacent,
so face 3, 4 and 5 are adjacent face.
But as per the diagram 1, face 4 and face 6 are adjacent faces.
Hence from the above it is clear that face 5 is the opposite face of face 6.