If the sum of the mean and the variance of a binomial distribution for 5 trials is 1.8 , then $p=$

The odds in favour of getting sum multiple of 3 , when pair of dice are thrown is

The rate of disintegration of a radio active element at time $t$ is proportional to its mass, at the time. Then the time during which the original mass of 1.5 gm . Will disintegrate into its mass of 0.5 gm . is proportional to

If $\mathbf{a}, \mathbf{b}, \mathbf{c}$ are non-coplanar vectors and $p=\frac{\mathbf{b} \times \mathbf{c}}{[a b c]}, q=\frac{\mathbf{c} \times \mathbf{a}}{[a b c]}, r=\frac{\mathbf{a} \times \mathbf{b}}{[a b c]}$, then $\mathbf{a} \cdot \mathbf{p}+\mathbf{b} \cdot \mathbf{q}+\mathbf{c} \cdot \mathbf{r}=$