A person can swim in still water at 4 km/h. If the speed of water 2 km/h, how many hours will the man take to swim back against the current for 10km?	Choose the correct choice.
A) 3  B) 5  C) 8  D) 9  E) 6
M = 4   S = 2   US = 4 - 2= 
<gadget id="calculator">4 - 2</gadget>
<output>2</output>
2   D= 10   T = 10/2= 
<gadget id="calculator">10/2</gadget>
<output>5</output>
5   Answer:5
<result>B</result>
A person can swim in still water at 4 km/h. If the speed of water 2 km/h, how many hours will the man take to swim back against the current for 10km?