What would happen if i calculate the rate of change on any interval of an exponential function

At a sale this week, a desk is being sold for $213. this is a 29% discount from the original price. what is the original price?

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label

What is the range? can’t seem to find it out