I have the other answers that I solved but I just need the top.

If g^-1(x) is the inverse of g (x) which statement must be true

You borrow $25,000 to buy a boat. the simple interest rate is 4%. you pay the loan off after 10 years. what is the total amount you paid for the loan?

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