1)How manyfour letter wordscan be formed from the word?proportion

2)How many committees of9 peoplecan be chosenfrom 12, iftwo certain people must never be in the same committee?

1) p is repeated twice, as is r, and o is repeated three times

so would it be 10C4 / (2!2!3!) to get rid of the double ups?

2) 1,2,3,4,5,6,7,8,9,10,11,12

lets say 1 is taken out, u have 11C9, and the same if two was taken out 11C9, and for the case where they are both together:10C9??

I need some help with this one.