Answer:
[tex]\huge\boxed{\sf f=4.8 \ Hz}[/tex]
Explanation:
Wavelength = λ = 6.25 × 10⁷ m
Speed of light = c = 2.998 × 10⁸ m/s
Frequency = f = ?
[tex]\displaystyle f=\frac{c}{\lambda}[/tex]
Put the givens in the formula.
[tex]\displaystyle f=\frac{2.998 \times 10^8}{6.25 \times 10^7} \\\\f=0.48 \times 10^1\\\\f=4.8 \ Hz\\\\\rule[225]{225}{2}[/tex]