What is the frequency of green light that has a wavelength of 531 nm? (c = 3.00 x 10⁸ m/s)

Miner's coal distributors does not mine coal itself, nor does it even store or handle the coal. instead, miner's solicits orders for low sulfur coal from other firms, then purchases the required amount from suppliers and directs them to ship the coal to its customers. what is miner's