Answer:
4 km/h
Step-by-step explanation:
We are told that Dina and Masha started out on a 10 km bike path at the same time.
Dina's biking speed is 5 km/h.
Let us find taken by Dina to cover 10 kn distance.
[tex]\text{Time}=\frac{\text{Distance}}{\text{Speed}}[/tex]
[tex]\text{Time taken by Dina to cover 10 km}=\frac{10km}{5\frac{km}{hr}}[/tex]
[tex]\text{Time taken by Dina to cover 10 km}=\frac{10km}{5}\times \frac{hr}{km}}[/tex]
[tex]\text{Time taken by Dina to cover 10 km}=2hr[/tex]
Therefore, Dina took 2 hours to complete 10 km.
Since both started at the same time, therefore, Masha also took 2 hours to complete 2 km less than Dina.
Let us find distance covered by Masha.
[tex]\text{Distance covered by Masha}=10\text{ km}-2\text{ km}=8\text{ km}[/tex]
Now let us find Masha's biking speed.
[tex]\text{Speed}=\frac{\text{Distance}}{\text{Time}}[/tex]
[tex]\text{Masha's biking speed}=\frac{8\text{ km}}{2\text{ hour}}[/tex]
[tex]\text{Masha's biking speed}=4\frac{\text{ km}}{\text{ hour}}[/tex]
Therefore, Masha's biking speed is 4 km per hour.
