Two different positions of the same dice are shown. What is the number of dots on the face opposite to the one with four dots?

3

Step 1) In figure 1 and 2, (4 dots) is common

Step 2) The number ‘4’ is common in both the dice. In order to find out, the number appearing on the opposite face, rotate the dice in a clockwise direction with the common number as the reference.

Step 3)  4        6        5

              4        1        2

Step 4)  

6  is opposite  to 1

5  is opposite  to 2

Therefore

4  will be opposite  to 3