A: "I remember that on a certain day in Winter both Celsius and Fahrenheit temperature readings showed the digit 5 as the units digit..."

B(after some mental calculation): "I'm certain it was not the coldest day..."

How cold was it?

(In reply to An aside, beyond the solution by Charlie)

Is it valid to assume that "winter" requires colder temperatures?  How about winter near the equator? Seems like all numerical solutions fit except those that are generally unrealistic for weather on earth, and also the one solution that would be the "coldest" reasonable solution.

Posted by Kenny M on 2018-01-06 21:14:38