Answer:
c. 0.0498
Step-by-step explanation:
First of all, let us find the number of four digit numbers possible.
There are 4 digits and let us have a look at the possibility of each digit.
Number of possible options for Unit's digit = 10
Number of possible options for ten's digit = 10
Number of possible options for hundred's digit = 10
Number of possible options for thousand's digit = 9 (because 0 can not be there to make it a 4 digit number)
Total number of possible outcomes = [tex]10\times 10\times 10\times 9 = \bold{9000}[/tex]
As per the given condition, unit's digit is 7.
So, number of possible options for unit's digit = 1
Number of possible options for thousand's digit = 8 (7 and 0 can not be there to make it a 4 digit number)
Number of possible options for hundred's digit = 8 (7 and one digit used in thousand's place can not be there)
Number of possible options for ten's digit = 7 (7, two digits used at thousand's and hundred's places)
Number of possible outcomes as per given conditions = [tex]1\times 8\times 8\times 7 = \bold{448}[/tex]
Formula for probability of an event E can be observed as:
[tex]P(E) = \dfrac{\text{Number of favorable cases}}{\text {Total number of cases}}[/tex]
[tex]P(E) = \dfrac{448}{9000} =\bold{0.0498}[/tex]
