Solution:
Solution
We have, $$np=25$$.
Now, $$0\le p<1$$ and $$0\le q<1$$
$$\Rightarrow 0\le npq\le np\Rightarrow 0\le \sqrt { npq } \le \sqrt { np } $$
$$\Rightarrow 0\le $$ S.D. $$\le 5$$.
But $$p\neq 0$$, therefore $$0\le $$ S.D. $$<5$$
$$\Rightarrow$$ S.D. $$\in [0,5)$$
