The number of P-P bonds and oxidation state of phosphorous in hypophosphoric acid  $\left({\text{H}}_{\text{4}}{\text{P}}_{\text{2}}{\text{O}}_{\text{6}}\right)$ respectively are

Structure of Hypophosphoricacid :

$\begin{array}{l}\mathrm{H}=+1,\\ \mathrm{P}=x,\mathrm{O}=-2\\ {\mathrm{H}}_2{\mathrm{P}}_2{\mathrm{O}}_6\Rightarrow 4+2x-12=0\\ \Rightarrow 2x-8=0\\ \Rightarrow 2x=8\\ \therefore x\left(\text{ oxidation number }\right)=4\\ \therefore \mathrm{P}-\mathrm{P}\text{ bonds }=1\end{array}$