The resistance of a conductor is 5 ohm at 50*c and 6 ohm at 100*c.Its resistance at 0*is??THANK YOU!!

Well, try thinking about it this way: the resistance changed by only ##1 Omega## over ##50^oC##, which is a pretty large temperature range. So, I would say it's safe to assume the change in resistance with respect to temperature (##(DeltaOmega)/(DeltaT)##) is pretty much linear.

##(DeltaOmega)/(DeltaT) ~~ (1 Omega)/(50^oC)##

##DeltaOmega = (1 Omega)/(100^oC-50^oC)*(0^oC-50^oC) ~~ -1 Omega##

##Omega_(0^oC) ~~ 4 Omega##