One person throws away 4.5 x 10² g/day.
In 2013, there were 3.2 x 10⁶ people, so they threw away
(4.5 x 10² g/day)*(3.2 x 10⁶) = 1.44 x 10⁹ g/day.
Assume that there were 365 days in 2013.
The total trash thrown away was
(1.44 x 10⁹ g/day)*(365 days) = 5.26 x 10¹¹ g
Answer: 5.3 x 10¹¹ g