Please solve the Molecular puzzle for each part of the equal sign, would really appreciate it?

Question

4 a) i) Mass of 3000 moles of Sodium nitrate =
ii) Add the mass of 1000 moles of Lead =
iii) Subtract the mass of 21346 moles
of Helium =

b) i) Mass of 24 moles of Ammonium fluoride =
ii) Add the atomic mass of Hydrogen plus
that of Oxygen =

c) i) Mass of 100 moles of Manganese =
ii) Add the molar mass of Lithium =

Answer 1

a) NaNO3 = 23+14+4*16=101
mass Of 3000NaNO3 =101*3000=303000g
mass of 1000 moles lead = 207000
mass of 21346 molesoh He =21346*4=85384
303000+207000-85384 =424616

b) mass of NH4F=14+4+19=37
24 moles= 37*24=888g
ii=888+32+2=912g

c) 100 moles Mn =55*100=5500

ii =5500+7 =5507