Answer:
The time taken is [tex]t_{out} = \frac{D}{v__{R}} + v__{S}}}[/tex]
Explanation:
From the question we are told that
The speed of the current is [tex]v__{R}}[/tex]
The speed of the swimmer in direction of current is [tex]v__{S}}[/tex]
The distance traveled by the swimmer is [tex]D[/tex]
The time taken to travel this distance is [tex]t_{out}[/tex]
The speed of the swimmer against direction of current is [tex]v__{s}}[/tex]
The resultant speed for downstream current is
[tex]V_{r} = v__{S}} +v__{R}}[/tex]
The time taken can be mathematically represented as
[tex]t_{out} = \frac{D}{V_{r}}[/tex]
[tex]t_{out} = \frac{D}{v__{R}} + v__{S}}}[/tex]