Jeff is choosing three numbers from the set {1, 2, 3, ..., 12}. How many ways can Jeff choose three numbers, so that no two chosen numbers are consecutive?
Example: 1 3 7
For the first number, you have 12 choices.
For the 2nd number, you have 10 choices [which excludes the first choice and its consecutive number]
For the 3rd number, you have only 8, choices [excluding the 1st and the 2nd and its consective number]
So, you have: 12 x 10 x 8 ==960 ways of picking 3 numbers out of 12.
