Question

The number of P-O-P bonds in Phosphorus trioxide and Phosphorus pentoxide are __________ and __________ respectively.
___

Answer 1

Let us look at the shapes of the $P_4{O}_6$ (exists as a dimer of $P_2{O}_3$ under normal conditions)

As you can see, in both the structures there are exactly six P-O-P bonds
Although they look similar, the O-P bond length (for the P-O-P linkage) is slightly smaller in the pentoxide as compared to the trioxide.