Margot measured the distance for 6 wavelengths of visible light as 2,400 nano meters what is the distance for 1 wavelength

In the next 10 month,colin wants to save $900 for his vacation.he plans to save $75 each of the first 8 months. how much must he save each of the last 2 months in order to meet his goal if he saves the same amount each month ?

Pleas ! i just cant seem to get it right! choose: congruent or proportional choose: cf or ce or bc choose: segment addition postulate or cpctc

Need me know if option a,b,c are wrong so ik its d