What is the probability of throwing exactly two 3x a two and 2x a three with five normal dice? Order is not to be respected (eg 22233=32322)

The possible combinations for n=6 and k=5, if order is to be neglected and repetition (as the task is about dice) is possible, is the formula (n+k-1 // k) which equals 720 possibilities. Thus the probability for axactly two threes and three twos is 1/720.

The solution is 10 //7776 though. Where is my mistake?

Thanks