Answer :
Hello!
First, let's analyze the exercise and get some important information:
• The kayaker’s speed while ,traveling upstream, is 4 miles per hour.
,• His speed ,going downstream, is 7 miles per hour.
Let's write it as a system with variables:
• k ,= speed of the kayaker
,• c, = speed of the current
[tex]\begin{cases}k-c=4 \\ k+c=7\end{cases}[/tex]If we add these two equations, we can cancel C, look:
[tex]\begin{gathered} 2k=11 \\ k=\frac{11}{2} \\ k=5.5 \end{gathered}[/tex]Now that we know the value of k, let's replace it in the first equation:
[tex]\begin{gathered} k-c=4 \\ 5.5-c=4 \\ 5.5-4=c \\ c=1.5 \end{gathered}[/tex]What is the kayaker speed still in the water? 5.5mi/h
What is the speed of the current? 1.5mi/h