Answer:

Explanation:
Given:
- average walking speed,

- average biking speed,

<u>According to given condition:</u>

where:
time taken to reach the building by walking
time taken to reach the building by biking
We know that,

so,



The properties of the wave don't determine its speed. The properties of the medium do. You can FIND the speed by measuring the wave's frequency and wavelength.
Answer:

Explanation:
Given that,
Wavelength, 
We need to find the frequency of the violet light.
We know that the relation between frequency and wavelength is given by :

So, the frequency of violet light is
.