Answer:
1. Upstream Time: 1 hour (or 60 minutes)
2. Downstream Time: 0.65 hour (or 39 minutes)
Step-by-step explanation:
The time it will take goes by the distance formula:
, where D is the distance, R is the rate (speed), and T is the time.
For Upstream, you are going <em>against</em> the current, so your still water speed slows down. So upstream rate is still water rate - stream rate. So 2.8 - 0.6 = 2.2mph
Time it will take him to swim 2.2 miles, is:
![D=RT\\2.2=2.2(T)\\T=\frac{2.2}{2.2}=1](https://tex.z-dn.net/?f=D%3DRT%5C%5C2.2%3D2.2%28T%29%5C%5CT%3D%5Cfrac%7B2.2%7D%7B2.2%7D%3D1)
So, 1 hour
For Downstream, you are going <em>with</em> the current, so your still water speed increases. So downstream rate is still water rate + stream rate. So 2.8 + 0.6 = 3.4 mph
Time it will take him to swim 2.2 miles, is:
![D=RT\\2.2=3.4(T)\\T=\frac{2.2}{3.4}=0.65](https://tex.z-dn.net/?f=D%3DRT%5C%5C2.2%3D3.4%28T%29%5C%5CT%3D%5Cfrac%7B2.2%7D%7B3.4%7D%3D0.65)
So, 0.65 hours (or 0.65*60=39 minutes)