This is determined using Newton's Law of Cooling - dT/dt=-k(T-a)
dT being the change in temperature
dt being the change in time
k being the proportional constant of the pot
T being the temperture at a given point in time
a being the constant temperature of the environment.
With what you have given us, the equation looks like this
60/dt=-k(170-37)
So it is quite difficult to solve for time when k is still a variable. Therefore simply plug in k(the proportional constant of the pot) and solve algebraically. The equation should be:
60/(-k(170-37))=dt
Hope this helps