Question

Dina and Masha started out on a 10 km bike path at the same time. When Dina reached the end of the 10 km, Masha still had 2 km to bike. If Dina's biking speed was 5km/h, find Masha's biking speed

Answer 1

4 km/h

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.

`\text{Time}=\frac{\text{Distance}}{\text{Speed}}`

`\text{Time taken by Dina to cover 10 km}=(10km)/(5(km)/(hr))`

`\text{Time taken by Dina to cover 10 km}=(10km)/(5)* (hr)/(km)}`

`\text{Time taken by Dina to cover 10 km}=2hr`

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.

`\text{Distance covered by Masha}=10\text{ km}-2\text{ km}=8\text{ km}`

Now let us find Masha's biking speed.

`\text{Speed}=\frac{\text{Distance}}{\text{Time}}`

`\text{Masha's biking speed}=\frac{8\text{ km}}{2\text{ hour}}`

`\text{Masha's biking speed}=4\frac{\text{ km}}{\text{ hour}}`

Therefore, Masha's biking speed is 4 km per hour.