The solid wall is 8 ft. * 20 ft. = <<8*20=160>>160 sq. ft.
The doorway is 3 ft. * 7 ft. = <<3*7=21>>21 sq. ft.
The window is 6 ft. * 4 ft. = <<6*4=24>>24 sq. ft.
The closet door is 5 ft. * 7 ft. = <<5*7=35>>35 sq. ft.
The total area of the doors and windows is 21 sq. ft + 24 sq. ft. + 35 sq. ft. = <<21+24+35=80>>80 sq. ft.
The solid wall is 160 sq. ft., so before the areas of the doors and window are taken into account, the total wall area is 4 * 160 sq. ft. = <<4*160=640>>640 sq. ft.
Taking into account the doors and window, the total wall area Linda will have to paint is 640 sq. ft. - 80 sq. ft. = <<640-80=560>>560 sq. ft.
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