A roast is taken from the refrigerator (where it had been for several days) and placed immediately in a preheated oven to cook. The temperature R = R(t) of the roast t minutes after being placed in the oven is given below.

R=375−340e−0.007t degrees Fahrenheit
What is the temperature of the refrigerator?
Express the temperature of the roast 20 minutes after being put in the oven in functional notation.
Calculate the value of the above term. (Round your answer to two decimal places.)
By how much did the temperature of the roast increase during the first 13 minutes of cooking? (Round your answer to two decimal places.)
By how much did the temperature of the roast increase from the first hour to 13 minutes after the first hour of cooking? (Round your answer to two decimal places.)