How many grams of nitrogen are in 2.00 grams of nitroglycerin c3h5n3o9

Molar Mass of Nitroglycerin 
C = 3*12 = 36 amu
H = 5*1 = 5 amu
N = 3*14 = 42 amu
O = 9*16 = 144 amu
----------------------------
Molar Mass of = 36+5+42+144 = 227 g/mol

Molar mass of all nitrogen = 42 g/mol

Solving: Rule of three (directly proportional)

2.00 grams ----------------- 227 g/mol
y grams --------------------- 42 g/mol

Product of extremes equals product of means:

227*y = 2.00*42
227y = 84.00
y = 

The answer is b i think