Ch 7

Question 1

Factorial notation

Answer 1

Let n be opposite integer than the product n(n-1)(n-2)…. 3.2.1 is denoted by n! And read as n factorial.

Question 2

Fundamental principle of counting

Answer 2

Suppose A and B are two events if event a can occur in P different ways and event be and occur in Q different ways the number of ways that two events can occur is the product P.Q

Question 3

Premutation definition

Answer 3

An ordered arrangement of a finite number of elements taken some or all the time is called premutation of these elements

Question 4

Combination

Answer 4

Let s be a set containing n elements and suppose r is a positive integer such as r ≤ n. Then any subset of s containing r distinct elements is called a combination of n elements taken r at a time

nCr= n!/r!(n-r)!

Question 5

Probability

Answer 5

Probability is the numerical evaluation of a chance that a particular event would occur

Question 6

Probability formula

Answer 6

P(A)= n(A)/n(S)

Question 7

addition Of probability formula

Answer 7

When a intersection b equals an empty set then .
P(AUB)=P(A)+P(B)

When a intersection b is not an empty set then
P(AUB)=P(A)+P(B)-P(A∩B)