A hash table with size 10 stores 6 elements. These 6 elements are stored in T[0], T[1], T[4], T[6], T[7], T[9]. Suppose that all the other entries contain no deleted flag. An entry has a deleted flag means that this entry stored an element before, but the element has already been deleted. If we would like to search an element with a key k and assume the linear probing technique is used, what is the expected number of probes for an unsuccessful search?