Question

HELP !!! Medal!

The temperature (in ° C) in a special oven to fire test evolves as a function of time t (measured in number of minutes after the oven is turned on).
The temperature as a function of time can be described by the rule:
f (t) = 20 +150 * ln (8t +1), where f (t) is the temperature and t is time.

a)Determine the temperature of the oven 10 minutes after the oven is turned on.
b) Explain what the number 20 in the regulation represents.
c) Determine how long it takes from the oven is turned on until the temperature reaches 500 celcius.