1. The problem statement, all variables and given/known data A source of sound mvoes along one straight line between listeners Abigail and Bertha. The wavelength of the sound waves heard by Abigail is about 1/2 the wavelength heard by Bertha. What is the ratio of of the speed of the source to the speed of sound? Assume that the air carrying the sound waves is stationary. 2. Relevant equations http://www.kettering.edu/~drussell/Demos/doppler/Eq1.gif [Broken] 3. The attempt at a solution So I know that the wavelength that Abigail observes is 1/2 the wavelength that Bertha observes. Neither of them are moving and the speed of sound is 343 m/s. I don't know how to tie these thoughts together to solve this problem.