A boat travels 72 km downstream in 8 hours and 84 km upstream in 12 hours. Find the speed of the boat in still water and the speed of the water current.  Choose the correct option
A) 8 km/hr, 1 km/hr  B) 5 km/hr, 4 km/hr  C) 1 km/hr, 6 km/hr  D) 2 km/hr, 1 km/hr  E) 4 km/hr, 1 km/hr
Downstream speed=72km/8hrs   =9kmph   upstream speed72  /8= 
<gadget id="calculator">72  /8</gadget>
<output>9</output>
9kmph   upstream speed=84km/12hrs   =7kmph   speed of boat84  /12= 
<gadget id="calculator">84  /12</gadget>
<output>7</output>
7kmph   speed of boat=avg of downstream and upstream speeds   speed of boat=(9+7)/2= 
<gadget id="calculator">(9+7)/2</gadget>
<output>8</output>
8kmph.   current speed=half of the difference of downstream and upstream speeds   currend speed=(9-7)/2= 
<gadget id="calculator">(9-7)/2</gadget>
<output>1</output>
1kmph   ans is 8km/hr,1km/hr   8 km/hr, 1 km/hrNSWER:8 km/hr, 1 km/hr
<result>A</result>
A boat travels 72 km downstream in 8 hours and 84 km upstream in 12 hours. Find the speed of the boat in still water and the speed of the water current.