Answer
$\frac{170g\ O_{2}}{1\ hour}$
Work Step by Step
$\frac{0.28g\ O_{2}}{1L\ air}\times\frac{0.50L\ air}{1\ breath}\times\frac{20\ breaths}{1\ minute}\times\frac{60\ minutes}{1\ hour}= \frac{170g\ O_{2}}{1\ hour}$
We use a series of relationships to find our answer.
