Question

$x$ is a temperature at which Centigrade and Fahrenheit scale read the same temperature. Then $x$ will be :

• A. $-40$
  
• B. $0$
• C. $98.6$
• D. None of the above
  

Answer 1

The correct option is A $-40$

Formula is $F=\frac{9}{5}C+32$

At x is same So $x=\frac{9}{5}x+32$

Or, $5x=9x+160$

Or, $9x-5x=-160$

Or, $4x=-160$

$x=-40$