Question: 1a find the u value of a wall that have...

1a) Find the U value of a wall that have its sections with the following materials with the R values per inch values below: R values for air film from outside and inside are 0.2 and 0.7. 1" stucco R=0.1 1.5" polystrene R=4.0 R-19 fiberglass R=19.0 0.5" gypsum board R=1.0