Please help!!!!

Calculate the 1000- to 850-hPa thickness for
a) an isothermal atmosphere with a temperature of 273 K.
b) an isothermal atmosphere with a temperature of 300 K.
c) an atmosphere with the constant lapse of Γ = 6.5 K km-1. The temperature and pressure
at the surface (z0 = 0 m) are T0 = 273 K and ps = 1000 hPa.
d) Compute the layer-mean temperature for the conditions in c).
e) Compare the three results: How do the thicknesses vary with temperature?

Question

Please help!!!!

Calculate the 1000- to 850-hPa thickness for
a) an isothermal atmosphere with a temperature of 273 K. 
b) an isothermal atmosphere with a temperature of 300 K. 
c) an atmosphere with the constant lapse of Γ = 6.5 K km-1. The temperature and pressure
at the surface (z0 = 0 m) are T0 = 273 K and ps = 1000 hPa. 
d) Compute the layer-mean temperature for the conditions in c). 
e) Compare the three results: How do the thicknesses vary with temperature?