A boat traveled 96 miles downstream and back. The trip downstream took 4 hours. The trip back took 12 hours. Find the speed of the boat in still water and the speed of the current

Respuesta :

Answer:

Speed of boat is still water: 16 miles per hour.

Speed of current: 8 miles per hour.

Step-by-step explanation:

Let x represent speed of boat in still water and y represent speed of current.

Downstream speed would be [tex]x+y[/tex].

Upstream speed would be [tex]x-y[/tex].

We have been given that a boat traveled 96 miles downstream and back. The trip downstream took 4 hours.  

[tex]\text{Rate}=\frac{\text{Distance}}{\text{Time}}[/tex]

[tex]x+y=\frac{96}{4}...(1)[/tex]

[tex]x+y=24...(1)[/tex]

We are also told that the trip back took 12 hours. We can represent this information in an equation as:

[tex]x-y=\frac{96}{12}...(2)[/tex]

[tex]x-y=8...(2)[/tex]

Upon adding equation (1) and equation (2), we will get:

[tex]x+x+y-y=24+8[/tex]

[tex]2x=32[/tex]

[tex]\frac{2x}{2}=\frac{32}{2}[/tex]

[tex]x=16[/tex]

Therefore, the speed of boat in the still water is 16 miles per hour.

Upon substituting [tex]x=16[/tex] in equation (1), we will get:

[tex]16+y=24[/tex]

[tex]16-16+y=24-16[/tex]

[tex]y=8[/tex]

Therefore, the speed of the current is 8 miles per hour.