1) How many three-digit numbers more than 600 can be formed by using the digits $2,3,4,6,7$?
2) How many number greater than a million can be formed with the digits $2,3,0,3,4,2,3$?
How could I distinguish between a repetition and non repetition permutation question?
E.g.: In first question repetition of digits is allowed, but in second repetition is not allowed (e.g. it can't have $3333333$).
Note: Please explain me how can I guess whether a question involves repetition or not,in general not only on this specific question.