Step 1 :The outcomes in F or G are \(\{3,4,5,6,7,8,9,10\}\).
Step 2 :The probability of F or G is calculated by dividing the number of outcomes in F or G by the total number of outcomes in the sample space. This gives us \(\frac{8}{12} = 0.6666666666666666\).
Step 3 :Rounding to three decimal places, the probability of F or G is \(\boxed{0.667}\).