The temperature of a city steadily drops during the day until it is half of what it was at the beginning of the day. It then decreases by an additional 6.8ºF after the sun goes down. The temperature at the end of the day is −3.1°F. What was the temperature at the beginning of the day?

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?