What is the wavelength of a wave that has a speed of 3kms and a frequency of 12hz?

The wavelength of a wave can be calculated using the formula: speed = frequency x wavelength. Given the speed is 3 km/s and frequency is 12 Hz, you can rearrange the formula to solve for wavelength: wavelength = speed / frequency. Plugging in the values gives you a wavelength of 0.25 km or 250 m.