Calculation of percentage heat reduction

Water at 90 C flows through a 50mm bore steel pipe of wall thickness 8 mm. Ambient temperature is 18 C. Calculate the heat loss per metre length of pipe. Assuming that the surface heat transfer coefficients remain the same when a layer of hair felt 25mm thick is wrapped around the outside of the pipe, calculate the percentage reduction in heat loss for the pipe when insulated in such a manner.
Data:

a) the thermal conductivity of steel is 45 W/mK.

b) the thermal conductivity of felt is 0.05 W/mK.

c) the outside surface heat transfer coefficient is 20.0 W/m2K.

d) the inside surface heat transfer coefficient is 2500 W/m2K.