Check out the midterm my students are taking tomorrow...

[gray_ghost]

1. Suppose a couple has two children. Find the probability that both children are boys if it is known that:
(a) At least one of the children is a boy
(b) The older child is a boy

Hint: The space of all possible outcomes is S = { bb,bg,gb,gg }

2. Suppose a student dormitory consists of:
60% first-year students (10% of whom own a car)
40% second-year students (20% of whom own a car)
Find the probability that a randomly selected student in the dormitory owns a car.

3. The Pentagon computer which you hacked into in the last homework assignment has become self-aware, and has come to the conclusion that human beings are a lower form of life which must be eradicated. To this end, it is attempting to guess the nuclear launch codes for all the nuclear missiles in the US nuclear arsenal (over which it has omniscient control).

The launch codes are of the form: XXX-XXX-XXX
The first block can be any combination of letters or digits.
The last two blocks must be numbers.

If the computer can try 2,000,000 codes a minute, how many minutes will it take before all possible codes have been tried?

4. If one card is drawn from a deck of 52 playing cards, what is the probability that you do NOT draw a face card or a heart?

5. In South Dakota Hot Lotto, 5 balls are drawn from one drum (the balls are 1-39), and a Hot Ball is chosen from a second orange drum (Hot Balls are numbered 1-19). What is the probability of picking all 5 numbers + Hotball?

6. Write down your first name. How many different permutations in the letters of your name are there?

7. If a coin is flipped 12 times, what is the probability that you get exactly 4 heads?

8. What is the probability that the sum of two rolled six-sided dice (numbered 1-6) is 10 or greater given that at least one of the rolled dice is a 5?




I just realized something. I am totally going to have to flock my journal in the future if I continue to teach. It is way too dangerous to have an open blog out there with a bunch of students who are probably online all the time, googling for their professor because they are bored and curious. *sigh*

Well for now - just this entry.

Comments

[katekat]

All I have to say is that you found Ian McDonald and you *didn't tell me*!?!?

Bastard.

But yeah, you'd be hard to find, I think. But I am not a crafty undergraduate with too much time on my hands. And I'm sure most of 'em have paid LJ's so they can search the location info. Sigh. You could opt not to display that (I think it's an option) or just choose Canada, since you're going to go there someday anyway.

[phendog.livejournal.com]

You can definitely opt not to fill in location. I never did.

[gray-ghost.livejournal.com]

Oh yeah...sorry. He was getting into a flamewar with a bunch of the hard SF types (which are loved so much on Slashdot), and giving them hell. So I found his link through there.