The distance ( s ) travelled by a particle in time $t$ is given by $S=4 t^2+2 t+3$. The velocity of the particle, when $t=3 \mathrm{sec}$ is

If $a^2 x^4+b^2 y^4=c^6$, then maximum value of $x y$ is equal to

If a number is drawn at random from the set $\{1,3,5,7, \ldots . .59\}$, then the probability that it lies in the interval in which the function $f(x)=x^3-16 x^2+20 x-5$ is stricly decreasing is

The equation of the normal drawn to the parabola $y^2=6 x$ at the point $(24,12)$ is