How many times faster will oxygen gas diffuse than carbon dioxide

Carbon dioxide diffuses 20 times faster than oxygen gas

It is estimated, however, that the diffusing capacity of carbon dioxide is from 400 ml to 450 ml per minute under resting conditions and the diffusion capacity for oxygen under resting conditions is 21 ml per minute.

Number of moles = 2.12 mol C3H8.
1 mol C3H8 = 6.02 × 1023 molecules C3H8.
1 molecule C3H8 = 11 atoms.
(3 carbon atoms and 8 hydrogen atoms)