Answer: Option 'a' is correct.
Explanation:
Since we have given that
Number of white side = 1
Number of red side = 2
Number of blue side = 3
Total number of sides of a coloured cube = 6
Probability of getting red side on a cube is given by
![(2)/(6)](https://img.qammunity.org/2019/formulas/mathematics/high-school/xulmxi4h1r87i2oqumko91sliyvwrpycbh.png)
so, there is 2 expected number of red sides out of every 6 on average over time.
Hence, Option 'a' is correct.