Simple temperature conversion problem

[coolbyte]

Homework Statement

I know this sounds too easy, but somehow webassign refuses my answers

The temperature difference between the inside and the outside of a home on a cold winter day is 64°F.

(a) Express this difference on the Celsius scale.
160/9

(b) Express this difference on the Kelvin scale.
2617/9

Homework Equations

C=5(F-32)/9
K=C+273.15

The Attempt at a Solution

Simply using the equations I got
C=160/9 or 17.7777778
K=2617/9 or 290.77777778

I inputted them three times in three forms, what is wrong with my answers?

 

[haruspex]

Your equations are for converting one temperature from one scale to another. What you are given is a temperature difference. Suppose it's T Deg F outside and T+64 inside, then try your equations on each and take the difference after conversion. What do you notice?

 

[coolbyte]

Thank you very much haruspex, I should have not subtracted 32 from the given temperature difference.
The right answer should be (64)(5/9)= 35.6