A group of volunteers are arranging stalls numbered 15 to 75(both inclusive) for a charity event. A participant chooses a stall number ‘k’ from this range. However, due to a coding rule in the event’s tracking system, the chosen stall must satisfy the following condition:

- The stall number k must share NO common divisor greater than 1 with at least 90% of all stall numbers in the range 15 to 75(both inclusive). How many values of k are possible?