Multiple choice general knowledge science & technology Centigrade & Fahrenheit scales give same reading at 40° 32° 273° 100° Reveal answer Fill a bubble to check yourself A Correct answer Explanation The Centigrade (Celsius) and Fahrenheit scales give the same reading at -40 degrees. Using the conversion formula F = (9/5)C + 32, setting F = C gives C = (9/5)C + 32, which solves to C = -40.