when the number of moles = mass/molar mass
so the number of moles of CO = mass of CO sample/molar mass of CO
when the mass of CO sample = 36.55 g
and the molar mass of CO = 12 + 16 = 28 g/mol
by substitution:
∴moles of carbon monoxide = 36.55 g / 28 g/mol
= 1.3 moles