Answer : The number of moles of phosphorous are 304 moles.
Explanation :
The formula of given compound is, 
In
compound, there 4 moles of phosphorus and 10 moles of oxygen.
As we are given that the moles of
is 76.0 mole. Now we have to determine the number of moles of phosphorous (P).
As, 1 mole of
has 4 moles of phosphorous
So, 76.0 mole of
has
of phosphorous
Therefore, the number of moles of phosphorous are 304 moles.