A girl swims downstream 48 km and upstream 18 km taking 6 hours each time; what is the speed of the current? Choose the correct choice from the following choices:  A) 2.2  B) 2.3  C) 2.1  D) 2.5  E) 2.4
48 --- 6 2.5S = 8   ? ---- 1   18 ---- 6 US = 3   ? ---- 1 S = ?   S = (8 - 3)/2= 
<gadget id="calculator">(8 - 3)/2</gadget>
<output>5/2 = around 2.5</output>
2.5   Answer:2.5
<result>D</result>
A girl swims downstream 48 km and upstream 18 km taking 6 hours each time; what is the speed of the current?