Kayla and Andrea both leave the library at the same time, but in opposite directions. If Andrea travels 5 mph faster than Kayla and after 7 hours they are 119 miles apart, how fast is each traveling?

Respuesta :

Answer:

Kayla: 6 mph

Andrea: 11 mph

Step-by-step explanation:

Let x represent Kayla's speed.

We have been given that Andrea travels 5 mph faster than Kayla, so Andrea's speed would be [tex]x+5[/tex] miles per hour.

We are also told that 7 hours they are 119 miles apart.

[tex]\text{Distance}=\text{Speed}\cdot\text{Time}[/tex]

Distance covered by Kayla in 7 hours would be [tex]7x[/tex] and distance covered by Andrea in 7 hours would be [tex]7(x+5)[/tex].

Since both are travelling in opposite direction, so we will add both the distances to find total distance as:

[tex]\text{Total distance}=7x+7(x+5)[/tex]

[tex]119=7x+7(x+5)[/tex]

[tex]119=7x+7x+35[/tex]

[tex]119=14x+35[/tex]

[tex]119-35=14x+35-35[/tex]

[tex]84=14x[/tex]

[tex]x=\frac{84}{14}[/tex]

[tex]x=6[/tex]

Therefore, Kayla is travelling at a rate of 6 miles per hour.

Andrea's speed would be [tex]x+5\Rightarrow 6+5=11[/tex]

Therefore, Andrea is travelling at a rate of 11 miles per hour.