Temperature Change: Convert 29°F to C and K

[planke]

Homework Statement

One day you notice that the outside temperature increased by 29° F between your early morning jog and your lunch at noon. What is the corresponding change in temperature in each of the following scales?

_____C
_____K

Homework Equations

Tc = (5/9)(Tf - 32)
T (kelvin) = Tc + 273.15

The Attempt at a Solution

Ti + 29F = Tf
Tf-Ti = 29F

Tc = (5/9)(29-32) = -1.66667C

I am confused to why this answer is incorrect.

 

[mgb_phys]

If you are only interested in a change of temperature you don't care about the zero points of the scales, you just need to know how many F is a C - and so how many C in 29F