(a)[2]
Determine how many different arrangements can be made from the 8 letters in TOMORROW.
(b)[3]
Find how many different arrangements of the 8 letters in TOMORROW have an R at the start and an R at the end, and where the three Os do not all occur together.
(c)[5]
Four letters are chosen at random from the 8 letters of TOMORROW. Find the probability that the chosen letters include at least one O and at least one R.