Consider two independent random variables $X$ and $Y$ having probability density functions uniform in the interval $[-1,1]$. The probability that $X^{2}+Y^{2}>1$ is
- $\pi / 4$
- $1-\pi / 4$
- $\pi / 2-1$
- Probability that $X^{2}+Y^{2}<0.5$
- None of the above