>>> from pollution import carbon_dioxide

>>> round(carbon_dioxide(2.1485), 3)
2.3

>>> round(carbon_dioxide(158.987), 3)
170.2

>>> oil_liters = 158.987*2
>>> round(carbon_dioxide(oil_liters), 3)
340.4

>>> oil_liters = 158.987/2
>>> round(carbon_dioxide(oil_liters), 3)
85.1

>>> oil_liters = 158.987/3
>>> round(carbon_dioxide(oil_liters), 3)
56.733

>>> oil_liters = 158.987*3
>>> round(carbon_dioxide(oil_liters), 3)
510.6

>>> oil_liters = 0
>>> round(carbon_dioxide(oil_liters), 3)
0.0

>>> oil_liters = 1
>>> round(carbon_dioxide(oil_liters), 3)
1.071

>>> oil_liters = 158.987*(1/74)
>>> round(carbon_dioxide(oil_liters), 3)
2.3