If each letter can be used more than once

Monday, 22 April 2019

6:58 PM

If each letter can be used more than once then how many 7-letter strings a) contain exactly one vowel? comb (7, 1) *perm (S, 1) A 6 X 216

 

a) The answer is the product of: • The number ofways to choose position forthe vowel: C(7, 1), • The number ofways to choose the vowel: 5 • The number ofways to fill the rest ofthe word with consonants: 216.

 

b) contain exactly two vowels? comb (7,2) x 52 x 21

 

b) The answer is the product of: • The number ofways to choose position fortwo vowels: C(7, 2), • The number ofways to choose two vowels: 5 • The number ofways to fill the rest ofthe word with consonants: 215.

 

 

Created with Microsoft OneNote 2016.