a) find the number of ways the word HISTORY can be arranged.7! = 5040
ways
b) Find the number of ways the word HISTORY can be arranged if the
letters O and R are
(i) together,There are
1. 6 things: H, I, S, T, OR, Y to arrange in 6! = 720 ways
Plus
2. 6 things: H, I, S, T, RO, Y to arrange in 6! = 720 ways
for a total of 1440 ways.
(il) not together(Number of arrangements of HISTORY) - (number of arrangements O and R are together.)
That's
5040 - 1440 = 3600 ways.
Edwin
