The temperature of a substance in an experiment changes by −8.7°F from 10 a.m. to 1 p.m. At 5 p.m., the temperature is 33.5°F. It is 23 of what the temperature was at 1 p.m.

What was the temperature at 10 a.m. of the substance?

Enter your answer as a decimal in the box.

°F