A: the spinner lands on red
If you spin the spinner twice, the results are independent, then the probability of getting two reds is P(A)*P(A)
We need this probability equal to 1/2 in order to get a fair game. Since there are 2 possible outcomes (red or blue), then P(A) = x/2. Now we can write the next equation:
![\begin{gathered} (x)/(2)\cdot(x)/(2)=(1)/(2) \\ (x^2)/(4)=(1)/(2) \\ x^2=(4)/(2) \\ x=\sqrt[]{2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/3dm8p3stdh59mh4m6vntdi2r0a7qnr7bsn.png)
This means that √2/2 of the spinner must be red