Answer:
The speed of Kayak in still water is 3.5 miles per hour .
Step-by-step explanation:
Given as :
The distance cover in downstream = 12 miles
The time taken to paddle downstream = 3 hours
The distance cover in upstream = 12 miles
The time taken to paddle upstream = 4 hours
Let the speed of Kayak in still water = x mph
And The speed of current = y mph
Now, Speed = [tex]\dfrac{\textrm distance}{\textrm time}[/tex]
For downstream
x + y = [tex]\dfrac{\textrm distance}{\textrm time}[/tex]
Or, x + y = [tex]\frac{12}{3}[/tex]
∴ x + y = 4 miles per hour ............A
For upstream
x - y = [tex]\dfrac{\textrm distance}{\textrm time}[/tex]
or, x - y = [tex]\frac{12}{4}[/tex]
∴ x - y = 3 miles per hour .........B
solving eq A and B
So, ( x + y ) + ( x - y ) = 4 + 3
Or, ( x + x ) + ( y - y ) = 7
Or, 2 x + 0 = 7
∴ x = [tex]\frac{7}{2}[/tex]
I.e x = 3.5 mph
so, speed of Kayak = x = 3.5 mph
Hence The speed of Kayak in still water is 3.5 miles per hour . Answer
