A person can swim in still water at 10 km/h. If the speed of water 4 km/h, how many hours will the man take to swim back against the current for 12 km?
Options:
A) 2	B) 7	C) 5	D) 9	E) 6
M = 10   S = 4   US =10 - 4= 
<gadget id="calculator">10 - 4</gadget>
<output>6</output>
6   D= 12   T = 12/6= 
<gadget id="calculator">12/6</gadget>
<output>2</output>
2   2nswer: 2
<result>A</result>
A person can swim in still water at 10 km/h. If the speed of water 4 km/h, how many hours will the man take to swim back against the current for 12 km?