8th grade math, please help.

Two friends are reading books. jimmy reads a book with 21,356 words. his friend bob reads a book with one-and-a-half times as many words. which expression represents the number of words bob reads?

Which of the following statements must be true about this diagram? check all that apply. x°, y°, z°, & w°

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