How many moles of p are in 2.4 moles of p2o10?

In order to solve this type of problem, we take a look at the subscript of each element involved in the compound. These values signifies the number of particles present of that element in that compound. The calculation is as follows:

2.4 moles P2O10 (2 moles P / 1 moles P2O10) = 4.8 moles P