Let the frequency be 'f' and wavelength be 'w'

 ,
 , 

w= 100 m and f = 3,000 kilohertz
Plug in the above values to find k
3000 = 
 
 
To find k, multiply both side by 100
3000(100) = k
k = 300,000
So equation becomes,
 
 
w= ? f = 500 kilohertz
500 = 
 
 
w = 
 
 
w = 600 m