Answer:
50%
Step-by-step explanation:
Since it was not a case of a Lettuce seed exposed first to red light and then to far-red light which will very likely not germinate because Pr (chromoprotein inactive form) absorbs red light efficiently, the light absorbed will convert a high proportion of the molecules to the Pfr (chromoprotein active form), thereby inducing germination. So there is a 50/50 percentage chance of of germination.