Many utility companies promote energy conservation by offering discount rates to consumers who keep their energy usage below certain established subsidy standards. a recent epa report notes that 70% of the island residents of puerto rico hae reduced their electricity usage sufficiently to qualify for discounted rates. if five residential subscribers are randomly selected from san juan, puerto rico, find the probability of each of the following events.

a. all five qualify for the favorable rate
b. at least four qualify for the favorable rates

Naruto is choosing between two venues that will deliver food to his house. with probability 1/3 he will choose ramen mania (r), and with probability 2/3 he will choose sushi (s). if he chooses r, 15 minutes after making the call, the remaining time it takes the food to arrive is exponentially distributed with average 10 minutes. if he orders s, 10 minutes after making the call, the time it takes the food to arrive is exponentially distributed with an average of 12 minutes. given that he has already waited 25 minutes after calling, and the food has not arrived, what is the probability that he ordered from r? i am really stuck on how to set this up, so if you could be extra clear, that would be super ! in advance