1. The problem statement, all variables and given/known data at t=0; thermometer reading (x) =80 F (taken outside where the air temp is 20 F) at t=3; x=42 F then the thermometer is brought inside where the air is at 80 F. at t=10; x=71 F When was the thermometer brought indoors? 2. Relevant equations temp=ambient temperature; x= present temp of the body x - temp=Ce-kt 3. The attempt at a solution first I get the value of k: t=0; x=80 x=Ce-kt +20 C=60 x=60e-kt +20; t=3;x=42 k=0.334 Now, when brought inside: at t=0, x=?? x-80=Ce-0.334t C=x-80 And I am currently stuck up in here. If answered, could someone explain how does it happen? Thanks in advance!