COSC 208 (Spring 2009)
HW 6
Due: 05/04/09
In the questions below suppose that a “word” is any string of seven letters of the alphabet, with repeated
letters allowed.
1.
How many words begin with A or B or end with A or B?
2.How many words begin with a vowel and end with a vowel?
3.How many words begin with a vowel or end with a vowel?
In the questions below suppose you have a class with 30 students — 10 freshmen, 12 sophomores, and 8
juniors.
4.In how many ways can you put all 30 in a line?
5.In how many ways can you put all students in a line so that the freshmen are first, the sophomores
are in the middle, and the juniors are at the end?
6.In how many ways can you get a committee of 7?
7.In how many ways can you get a committee of 4 freshmen and 3 sophomores?
In the questions below (8 – 12) suppose you have 30 books (15 novels, 10 history books, and 5 math
books). Assume that all 30 books are different. In how many ways can you
8.In how many ways can you put the 30 books in a row on a shelf?
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 Anafi/Quinlan
 Serial number

Click to edit the document details