The access code for a​ car's security system consists of six digits.  The first digit cannot be 5 and the last digit must be odd. How many different codes are​ available?  (Note that 0 is considered an even​ number.) Can  you please  explain this probability to me of this question.  Thank you.

Please help with explanation

There are 3 light switchas in a row and each switch can either be On or Off. Use information to answer parts a and b below.  Part A: when considering all possible light switch settings, give the probability of having at least one light switch On. Part B: when considering all possible light switch settings, and using odd notation, give the odd in favor of having exactly one light switch On

At bedtime, you read three books to your kids, Walker, Michael, and Luke. Together, they have 32 books. If you decide to randomly choose three books, what is the probability that the three you choose will consist of each of their favorite books? Assume they have different favorites. Express your answer as a fraction in lowest terms or a decimal rounded to the nearest millionth.

Please solve the last 3 options