How many moles of magnesium phosphate, Mg_3(PO_4)_2 will contain 0.25 mole of oxygen atoms ?

How many moles of magnesium phosphate, Mg_3(PO_4)_2 will contain 0.25

1.	How many moles of magnesium phosphate, Mg_3(PO_4)_2 will contain 0.25 mole of oxygen atoms ?
Answer» 0.02 `3.125 XX 10^(-2)` `1.25 xx 10^(-2)` `2.5 xx 10^(-2)` ANSWER :B