Step 1;calculate the molar mass of NH4N03
molar mass of different element
N=14
H=1
O=16
therefore molar mass of NH4NO3 is 14+4+14+48= 80g/mol
step 2:find the molar mass of N present in NH4NO3
That is 14+14 =28g/mol
the mass is therefore
{(28g/mol/80g/mol) x 89g} =31.15g
