permutation/combination There are six cards with numbers written on them: $1, 2, 3, 4, 5, 6$ .
Two of them are drawn at at time and put together to form fractions, e.g. $\dfrac45$
How many proper fractions can be formed?
What is correct equation to solve this type of questions?
thanks

The total ways are 6P2=30. So for a perfect fraction we need  numerator< denominator so 6 cannot be numerator so 5 possibilities are directly eliminated . Now note the order for 6 we have 0 possibilties for 5 1 for 4 2 possibilities till for 1 we have 5 possiblities so answer is $0+1+2+3+4+5=15$ thats the answer to your question there are 15 perfect fractions.
