Consider a game of tossing a six sided fair die. If the face that comes up is $6$, the player wins Rs. $36$ and he loses Rs. $k^2$, where $k$ is the face that comes up $k = \{1, 2, 3, 4, 5\}$, then the expected winning amount in this game in Rs. is...

For two vectors $\vec{P}$ and $\vec{Q}$, $\vec{P} \cdot \vec{Q} = |\vec{P} \times \vec{Q}|$
The magnitude of $\vec{R} = \vec{P} + \vec{Q}$ is ($\cos 45^\circ = \dfrac{1}{\sqrt{2}}$) ?

Two stones of masses $m$ and $3m$ are whirled in horizontal circles, the heavier one in a radius $\dfrac{r}{3}$ and the lighter one in radius $r$. When both the stones experience same centripetal forces, the tangential speed of lighter stone is '$n$' times that of the value of heavier stone. The value of '$n$' is

Two particles having mass 'M' and 'm' are moving in a circular path with radius 'R' and 'r' respectively. The time period for both the particles is same. The ratio of angular velocity of the first particle to that of the second particle will be