How many of the following molecules / ions have trigonal planar structure?

$$ \mathrm{BO}_3^{3-}, \mathrm{NH}_3, \mathrm{PCl}_3, \mathrm{BCl}_3, \mathrm{ClF}_3, \mathrm{XeO}_3 $$

Consider the following

Assertion (A) Dipole moment of $\mathrm{NF}_3$ is lesser than $\mathrm{NH}_3$.

Reason (R) In $\mathrm{NF}_3$, the orbital dipole due to lone pair of electrons is in the opposite direction to the resultant dipole moment of the three $\mathrm{N}-\mathrm{F}$ bonds.

The correct answer is

At $\mathrm{T}(\mathrm{K})$, a gaseous mixture contains $\mathrm{H}_2$ and $\mathrm{O}_2$. The total pressure of the mixture is 2 bar. The partial pressure of $\mathrm{H}_2$ is 1.778 bar. What is the weight $(w / w)$ percentage of $\mathrm{H}_2$ in the mixture?