What is the concentration of sodium phosphate contains 0.60 M Na+?

I'm not sure what to do and how to figure how to do this question.

Sodium phosphate has a chemical formula

Na2PO4

Calculating the concentration of sodium phosphate given a concentration of sodium ions can be done using dimensional analysis

0.60 moles/L Na + (1 mole Na2PO4 / 2 moles Na+) = 0.30 moles/L Na2PO4

=.030 M Na2PO4