He uses 1 tablespoon for weak coffee and doubles that for strong so the strong uses 1*2 = <<1*2=2>>2 tablespoons
For the weak coffee he uses 1 tablespoon per 1 cup of water and he needs to make 12 cups so he'll use 1*12 = <<1*12=12>>12 tablespoons
For the strong coffee he uses 2 tablespoons per 1 cup of water and he needs to make 12 cups so he'll use 2*12 = <<2*12=24>>24 tablespoons
All total he will use 12 tablespoons for the weak coffee and 24 tablespoons for the strong coffee for a total of 12+24 = <<36=36>>36 tablespoons
#### 36