​Six numbers, 7, 8, 9, 10, 11 and 12 are written on different faces of a dice. Three positions of this dice are shown here. Find the number on the face opposite 7.

Logic: In these types of dice problems, we should write all three numbers/letters in clockwise or anticlockwise from a fix common number/letter.

7 is common in second and third positions.

From second and third positions,

So, 9 is on opposite face of 7.

Thus, correct option is (a).