Twenty-one percent of vacationers say the primary purpose of their vacation is outdoor recreation.  You randomly select 10 vacationers and ask each to name the primary purpose of his or her vacation.  To three significant digits, find the probability that the number who say outdoor recreation is the primary purpose of their vacation is:

1. exactly three.
   {#1}
   
   
2. more than three.
   {#2}
   
   
3. at most three.
   {#3}