Answer:
2
Step-by-step explanation:
The number of oranges he has is a multiple of 6, so the number can be
6, 12, 18, 24, 30, 36, 42, 48, 54, etc.
He sells one orange, so now he an have:
5, 11, 17, 23, 29, 35, 41, 47, 53, etc.
All numbers above up to 53 are multiples of 1, so n can be 1.
Also 5 and 35 are multiples of 5, so n can be 5.
All numbers other than 5 and 35 are prime.
Answer: 2
