Letters A-J are put into a bag, 5 are selected at random (without replacement) to form a 5letter word:
A. How many different words are possible ?
B. What is the probability the word ENDS with a vowel?
C. What is the probability it starts and ends with a vowel?
a) number of possible words = 10x9x8x7x6 = 30240
b) I will assume that it will end in a vowel, but could have other vowels elsewhere.
number with vowel at the end
= _x_x_x_x 3
= 7x6x5x4x3
= 2520
Prob(end with a vowel) = 2520/30240 = 1/12
c) 3 x _ x _ x _ x 2
= 3x8x7x6x2 = 2016
Prob(start and end with a vowel) = 2016/30240 = 1/15