A Sample of Ca3(PO4)2 contains 3.1g phosphorus then the weight of Ca in the sample is ?

A Sample of Ca3(PO4)2 contains 3.1g phosphorus then the weight of Ca in the sample is ?

We know that, moles = `"g"/"molar mass"`.

There are two moles P atoms per mole Ca3(PO4)2 and 3 moles Ca atoms per mole Ca3(PO4)2,

then `1/2` P moles will be moles Ca3(PO4)2 and 3x that value will be moles Ca atoms.