MATH 399N Week 3 Homework Solutions: → Spring 2017
The access code for a car's security system consists of six digits. The first digit cannot be 9 and the last digit must be odd.
Q. How many different codes are available?
A. 450000
how many events occur? 6 (6 digits)
how many choices are there for the first digit? 9 (0,1,2,3,4,5,6,7,8)
how many choices are there for the 2^{nd}, 3^{rd}, 4^{th} and 5^{th}? 10 (09)
how many choices are there for the last digit? 5 (1,3,5,7,9)
9*10*10*10*10*5 (multiple the number of choices for each digit)
A probability experiment consists of rolling a 6sided die. Find the probability of the event below.
rolling a number less than 5
Q. What is the probability?
A. 0.667
number of outcomes in event E/Total number of outcomes in sample space
6 outcomes in the sample space/4 outcomes for rolling less than 5
Q. If two events are independent, P(AB) =P(B)
A. False; if events A and B are independent, then P (A and B) = P(A) * P (B)
 
 Nonnursing majors  Total 
 
Males  93  1061  1154 

Females  723  1629  2352 

Total  816  2690  3506 

Q.
Find the probability that a randomly selected student is male, given that the student is a nursing major.
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