1. The problem statement, all variables and given/known data In one internet site it is 1-propyl-2-methylcyclopentane and in other it is 1-ethyl-2-propylcyclohexane 2. Relevant equations 3. The attempt at a solution I know when two different substituents could receive the same number, number them by alphabetical order. So I can understand 1-ethyl-2-propylcyclohexane but it contradict with 1-propyl-2-methylcyclopentane. Are they both right?