What is 89 Fahrenheit in Celsius?

2 Answers
Sep 20, 2015

32^@"C"32C

Explanation:

Celcius to Farenheit conversion

(C-0)/(100-0)=(F-32)/(212-32)C01000=F3221232

C/100=(89-32)/180C100=8932180

C=57/180*100=57/9*5=95/3 ~= 32^@"C"C=57180100=5795=95332C

Sep 20, 2015

T_C=31.666... degree Celsius.

Explanation:

This should be in the Physics section but anyway...

For this, you need to know the formula that converts Fahrenheit to Celsius.

Googling it, you will easily find that:
T_C=(T_F - 32)*frac(5)(9)

where T_C is the temperature in Celsius,
and T_F is the temperature in Fahrenheit.

So, since T_F=89, we have:

T_C = (89-32)*frac(5)(9)
so
T_C = 57*frac(5)(9)

I'm sure most people would pull out their calculator at this stage, but we could simplify it a bit more, if one notices that 57 = 30 +27 = 3*10+3*9=3*19.
Then we can simplify the 3 (because 9=3*3) and we have:
T_C = 19*frac(5)(3)

Then 19*5=95, and we are left with:
T_C = frac(95)(3)

You could bust out your calculator at this point but we could go a bit further, if one notices that 95=93+2 where 93 is a multiple of 3.
T_C=frac(93)(3)+frac(2)(3)

Since frac(93)(3)=31 and you do know that frac(2)(3)=0.6666... (well, you must know that frac(1)(3)=0.33333... so that frac(2)(3)=0.66666...),
we have:

T_C=31.666... degree Celsius.