The speed of the boat in still water in 12 kmph. It can travel downstream through 42 kms in 3 hrs. In what time would it cover the same distance upstream?  Pick:
A) 8 hours
B) 6 hours
C) 4.2 hours
D) 5 hours
E) 6 hours
Still Water=12km/hr   Downstream=42/3= 
<gadget id="calculator">42/3</gadget>
<output>14</output>
14km/hr   Upstream=&gt;&gt; still water=(u+v/2) =&gt;&gt; 12=u+14/2 = 10km/hr   So time taken in upstream = 42/10= 
<gadget id="calculator">42/10</gadget>
<output>21/5 = around 4.2</output>
4.2hrs   ANSWER:4.2 hours
<result>C</result>
The speed of the boat in still water in 12 kmph. It can travel downstream through 42 kms in 3 hrs. In what time would it cover the same distance upstream?