Suppo, e that in winter the daytime temperature in a certain office building is maintained at 70°f, the heating
is shul off at 10 p. m. and tumed on again at 6 a. m. on a certain day the temperature inside the building at
2 a. m. was found to be 65°f. the outside temperature was 50°f at 10 p. m. and had dropped to 40°f by 6 a. m.
what was the temperature inside the building when the heat was turned on at 6 a. m.?