Avery uses an online account to rent movies. He is charged the same amount for each movie he rents. Last month he rented 8 movies and his account balance changed by -32 in all. Avery wants to know the change in his account balance for each movie
-32 divided by (-8) -32 * (-8)
-32 divided by 8 -32 * 8

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