Need help on Thermodynamics problem: thermal expansion to be more specific

[Juniorphysics]

Need help on Thermodynamics problem: thermal expansion to be more specific!

A steel ring with a 2.5000in- inside diameter at 20.0°C is to be warmed and slipped over a brass shaft with a 2.5015in outside diameter at 20.0°C.
Part A:

To what temperature should the ring be warmed?

Part B:

If the ring and the shaft together are cooled by some means such as liquid air, at what temperature will the ring just slip off the shaft?

Attempt at solution:
using dL=alphaL_idT
i converted the diameters to meters because i was given alpha in m/m°C. so i got d₁=0.0635m d₂=0.0635381m and dL=0.0000381m
i used alpha=13*10^-7m/m°C
and got dT to be 45.9 but that gave me the incorrect answer

 

[Doc Al]

and got dT to be 45.9 but that gave me the incorrect answer

Double check your arithmetic. (FYI: No need to change units for the lengths.)

 

[Juniorphysics]

It gave me the same answer

 

[Doc Al]

Show your calculation. You are off by about a factor of 10.