how many 6 person committees are possible from a group of 8 people
a)there are no restrictions
b)both jim and mary must be in the group
c)either jim or mary (not both) must be on the committee

Question

how many 6 person committees are possible from a group of 8 people
a)there are no restrictions
b)both jim and mary must be in the group
c)either jim or mary (not both) must be on the committee

anonymous · Answer

a) 8C6

anonymous · Answer

if both jim and mary are in it, then you have 4 open places out of 6 so second one is 
$$\dbinom{6}{4}=\frac{6\times 5}{2}=15$$

anonymous · Answer

both of the responese are great. Thank you ShaileshAR and Satellite

anonymous · Answer

so how would I compute C??

anonymous · Answer

if jim must be in it and mary must not be, then you have 5 spots to fill and 6 people to choose from

anonymous · Answer

so that one is $\dbinom{6}{5}=6$ 
the other is identical, so your answer should be $2\times 6$

anonymous · Answer

Ok i get it. Thanks for breaking it down exactly