## Elementary Technical Mathematics

$$25 \times 10^{3} \ ns.$$
Since 1 $\mu s$= $10^{-6} \ s$ and $1~n s= 10^{-9} \ s$ W, we have $$25 \ \mu s= 25 \times 10^{-6} \ s= 25 \times 10^{-6} \times 10^{9} \ ns =25 \times 10^{3} \ ns.$$