In: Statistics and Probability
Q‒1. [2×10 marks] In the questions below suppose that a “word” is any string of seven letters of the alphabet, with repeated letters allowed.
a) How many words begin with R and end with T?
b) How many words begin with A or B?
c) How many words begin with A or end with B?
d) How many words begin with A or B and end with A or B?
e) How many words begin with A or B or end with A or B?
f) How many words begin with a vowel and end with a vowel?
g) How many words begin with a vowel or end with a vowel?
h) How many words begin with AAB in some order?
i) How many words have no vowels?
j) How many words have exactly one vowel?