Three different numbers are chosen from 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. How many ways can the numbers be chosen so that no 2 of the 3 numbers are consecutive?
I'm completely stumped when it comes to this question. How do you deal with this kind of restriction? BTW, this is a combinations question (order of numbers picked does not matter). Thanks!