Answer:
First option: 1*10^(-10) m
Explanation:
y=3*10^8/x
Wavelength (in meters): x=?
Frequency: y=3*10^18
Replacing y by 3*10^18 in the equation:
3*10^18=3*10^8/x
Solving for x: Cross multiplication:
3*10^18*x=3*10^8
Dividing both sides of the equation by 3*10^18:
3*10^18*x/(3*10^18)=3*10^8/(3*10^18)
Simplifying:
x=10^8/10^18
x=10^(8-18)
x=10^(-10)
x=1*10^(-10) m