The train ride takes Andrew 2*10 = <<2*10=20>>20 hours.
Together, the subway ride and the train ride take Andrew 10+20 = <<10+20=30>>30 hours.
With an additional bike ride of 8 hours to reach the Bronx, Andrew takes 30+8 = <<30+8=38>>38 hours to travel from Manhattan to the Bronx.
#### 38