Which of the following alkenes is most easily formed by dehydrohalogenation of alkyl halides?

The Cartesian equation of plane through $\mathrm{A}(7,8,6)$ and parallel to the XY plane is

The number of ways, in which 6 boys and 5 girls can sit at a round table, if no two girls are to sit together, is

If $\left[\begin{array}{lll}2 \bar{p}-3 \bar{r} & \bar{q} & \bar{s}\end{array}\right]+\left[\begin{array}{lll}3 \bar{p}+2 \bar{q} & \bar{r} & \bar{s}\end{array}\right]=m\left[\begin{array}{lll}\bar{p} & \bar{r} & \bar{s}\end{array}\right] +n\left[\begin{array}{lll}\bar{q} & \bar{r} & \bar{s}\end{array}\right]+t\left[\begin{array}{lll}\bar{p} & \bar{q} & \bar{s}\end{array}\right]$, then the values of $\mathrm{m}, \mathrm{n}, \mathrm{t}$ respectively are ....