23. Albert's monthly cell phone bill, y dollars, in terms of the number of minutes of talk time, x, is represented by the equation y = tx + b. In a particular
month, he paid $30 for 100 minutes of talk time. In another month, he paid
$60 for 250 minutes of talk time.
a)
Write the related system of linear equations.
b) Find the values of x and b.
Albert paid $40 in a particular month. For how many minutes of talk
time was he charged that month?

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