PROPOSITIONS
it has 2 P's, 3 O's, 2 S's, 2 I's, 1 R, 1 T, 1 N
Using the letters in "PROPOSITIONS"
a) How many of the distinguishable arrangements have the two Ps adjacent and the three O's adjacent?
That's the distinguishable arrangements of these 9 things
{PP,OOO,R,S,S,I,I,T,N}
The two S's are indistinguishable and the two I's are indistinguishable:
That's
= 90720
b) How many of the distinguishable arrangements do not have the two Ps adjacent?
First we find the number of distinguishable arrangements:
= 9979200
Next we find the number that have the 2 P's adjacent.
That is the number of distinguishable arrangements of these 11 things
{PP,O,O,O,S,S,I,I,R,T,N}
The 3 O's, the 2 S's and the 2 I's are indistinguishable:
That's
= 1663200
So we subtract
9979200 - 1663200 = 8316000
Answer: 8316000
Edwin