3) (16 pts) In a psychological experiment, participants were shown a series of images of common household items and asked to recall them each minute after the experiment. The percentage of participants who recalled the images after t minutes is given by the equation R(t) = 80 - 20 Int. a. What percentage of participants recalled the images after 1 minute? Round to 2 decimal places, if necessary. b. Calculate R'(3) and explain its meaning in a complete sentence. C. How long will it take for all participants to forget the images? Give the EXACT answer and then round to one decimal place