C5H12  +8O2 → 5CO2   + 6H2O
formula

Complete combustion of pentane: C5H12 + 8O2 → 6H2O + 5CO2 ... balanced equation

moles C5H12 used = 10.0 g C5H12 x 1 mol/72 g = 0.139 moles pentane

moles O2 consumed = 0.139 mol C5H12 x 8 mole O2/1 mol C5H12 = 1.11 moles O2

mass O2 consumed = 1.11 moles O2 x 32 g/mole = 35.5 g O2

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be