A random variable $X$ has the following probability distribution:

| $X$ | $1$ | $2$ | $3$ | $4$ | $5$ |
|---|---|---|---|---|---|
| $P(X)$ | $k^{2}$ | $2k$ | $k$ | $2k$ | $5k^{2}$ |

Then $P(X \geq 2)$ is equal to: