Of the 30 students in the sixth period math class, 8 are also in the same fourth period science class. Which can be
used to determine the probability that if three students are chosen at random from the math class to do a group
project, the first student chosen to be in the group is in the fourth period science class but the other two are not?
a [8/30][22/29][21/28
b [8/30][8/30][8/30]
c [8/30][7/29][6/28]
d [8/30][22/30][21/30]