Transcript Chapter IV - 02 - Qatar University

Exercise (1)
Let A = {1,3,4,5}, B = {2,6,7,8,9 }and C = {1,2,3,7,8}, D = { 6, 7, 8 }
Find n(AUB), n(AUC), n(BUC}, n(AUD), n(BUD), n(CUD) and show that
this is consistent with the formula for n(AUB)
Exercise (2)
In a certain semester, a professor teaches
only two classes, class A and class B
There are 26 students in class A. In class
B there are 20 students, five of which are
also in class A. How students this
professor have in this semester?
Exercise (3)
Three highways connect towns A & B, three
connect B & C, 3 connects C & D and 3
connects D & E. How many distinct routes
one can choose from to drive from A to G
Exercise (4)
Find:
1. The permutation of 8 objects taken 7 at a time
2. p(7,4)
3. p(5,5) = 5! = 120
4. Let A = { 1,2,3,4,5}
Compute the number of permutations of the set A taken 2
at a time
5. From 5 distinct positive integers, how many 3-digit
numbers, we can make, provided no integer appears
twice in the number?
6. From 5 different letters, how many 5-letter words
(meaningful or otherwise), we can make provided no
letter appears twice in the word?
Exercise (5)
Compute the number of permutations that can be formed
from all the letters of the phrase: Very Interesting
Exercise (6)
1. Find:
a. C(7,3)
b. C(7,7)
2. From a number of 9 people, 3 people are to be selected
for some task. Compute the number of ways to do that