75ºF = 315ºK
1) If the temperature is 75F, then let's apply the following rule to convert it to Kelvin.
C+273=K, F=1.8C + 32
2) Since we have these two equations we can use them and solve for K plugging in the second equation C = 5/9 F

Notice that, we have transformed the fraction into decimal numbers. 125/3 is equal to 41.67.