In a study, we are interested in the reaction time for participant taking a specific drug A. We would like to study the participants who had a reaction time less than 0.5 seconds. Therefore, across a sample of 25 participants, we categorized yes/no on those participants who had a reaction time less than 0.5. It is thought that, in general, 25% have a reaction time less than 0.5 seconds.

1. What is the probability that at least 1 participants have reaction times less than 0.5 seconds?

1. What is the probability at most 2 participants have reaction times less than 0.5 seconds?

1. What is the probability that exactly 5 or exactly 6 people have reaction times less than 0.5 seconds?