Business Statistics

176 Business Statistics

E

1

is the event of getting a sum of 9 and it can be obtained in four ways. So,

E

1

= (3, 6) (4, 5) (5, 4) (6, 3)

E

2

is the event of getting a sum of 10 and it can be obtained in three ways. So

E

2

= (4, 6) (5, 5) (6, 4)

There is no common element among the possible outcomes of E

1

and E

2

. Hence

1 2

( )E E = 

and

1 2

( ) 0P E E =

So, the required probability is

1 2 1 2

( ) ( ) ( )P E E P E P E= +

where

1

4

( )

36

P E =

and

2

3

( )

36

P E =

1 2

4 3 7

( )

36 36 36

= + =P E E

Self-Practice ProblemS

5B1. In a die rolling experiment, calculate the probability of get-

ting 4 on the upper face of the die.

5B2. In a simultaneous throw of two ...