Question 23730
It's a binomial problem with n=32, p=0.9.
You want the probability the number of 
successes (people showing up) is greater
than 30.  There are several ways to get 
this answer, depending on the techniques 
you have studied.
If you have a TI-83 calculator use:
1-binomcdf(32,0.9,30)= 0.156 = 15.6%

Cheers,
Stan H.