A person can row at 10 kmph in still water. If the velocity of the current is 2 kmph and it takes him 30 hour to row to a place and come back, how far is the place?
Choose the most appropriate option.
A) 144km B) 30km C) 48km D) 12km E) 15km
Speed of down stream = 10+2= 
<gadget id="calculator">10+2</gadget>
<output>12</output>
12kmph   speed of upstream= 10-2= 
<gadget id="calculator">10-2</gadget>
<output>8</output>
8kmph   Let the required distance be xkm   x/12 + x/8= 30   2x+3x = 720   x = 144 km   144kmnswer is 144km
<result>A</result>
A person can row at 10 kmph in still water. If the velocity of the current is 2 kmph and it takes him 30 hour to row to a place and come back, how far is the place?