Question 354257
each committee leaves out 2 of the 9 doctors


there are 9 ways to leave out one doctor


for each of those 9 ways , there are 8 ways to leave out the second doctor
___ so 72 ways
___ BUT ... leaving out Dr. Smith and then Dr. Jones , is the SAME as leaving out Dr. Jones and then Dr. Smith


so the possible committees is 72/2