Monthly Archives: October 2014

Puzzle #73: Hallowe’en Candy Calling

You just bought a big bag of 200 candies for handing out on Hallowe’en. Unfortunately, you have somewhat of a sweet tooth, and you raid the bag twice per day, each time taking from three to five candies.

What is the probability that the bag will run out before Hallowe’en evening? (Assume that your first daily raids are on October 15th and your last daily raids are on October 31st.)

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, October 29, 2014 at noon Pacific Time. I will post the answer shortly after.

Puzzle #71 Solution: Midterms

Spoiler Inside: Solution to Puzzle SelectShow

Memes Stopping Thought

Some ideas (memes) gain wide acceptance without enough criticism.

One example of this is one connected with Open Source software. Supposedly, there are a lot of eyes on Open Source software, and bugs are more easily detected. This advantage has been claimed many times, sometimes with considerable snideness toward closed source software.

However, there have been some nasty problems recently with some Open Source software. (One example of this is the Shellshock bash bug, and this is hardly the only one.)

Many people who use Open Source software never do look at the code, and even if one does, some bugs can be very subtle. If a bug requires that one be familiar with a highly technical field, such as cryptography, it may be that few people can find such bugs, and they might not be looking for them.

If an idea seems too good to be true, it just might not be true. There is no software panacea, much as we might want one.

Odd Language #69: Other Impressions

I saw on a van a URL: chubbedwards.com.

The issue: The van was a company van of the security firm Chubb Edwards. Unfortunately for them, I saw the URL before the company name. I parsed it as “chubbed wards”. There was a bit of confusion until I saw the company name. If the traffic had been faster, I might not have seen the company name.

Puzzle #72: Marbles

You have a collection of marbles. Each marble is of one colour: red, orange, yellow, green, blue, or violet.

1) The number of yellow marbles plus the number of blue marbles equals the number of green marbles.
2) There are at least two and at most nine marbles of each colour.
3) The number of red marbles plus the number of blue marbles equals the number of yellow marbles.
4) The number of yellow marbles is odd.
5) The number of orange marbles plus the number of yellow marbles equals the number of violet marbles.
6) The number of red marbles and the number of blue marbles are not equal.
7) There are either three colours with the same number of marbles, or there are two pairs of numbers of marbles.
8) There is an odd number of marbles for three of the colours, and an even number of marbles for three of the colours.

How many marbles of each colour do you have?

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, October 22, 2014 at noon Pacific Time. I will post the answer shortly after.

Puzzle #70 Solution: Candy

Spoiler Inside: Solution to Puzzle SelectShow

Please Document!

I like good documentation. With good documentation, it is easy to figure out how to do something. Without it, it may be nearly impossible.

Unfortunately, a lot of things are left undocumented.

Try reading most programs. The commenting can be very minimal, if not totally absent. It can take a lot of time to figure out such a program as one must take it apart.

The same frustration applies to processes on the job. “Everybody knows” so it does not get documented. This is rather hard on new employees.

How much time have you wasted because you did not have documentation for something?

If you are a person creating something, please document it. You know it better than anyone else, and you will save many people a lot of time.

Which might be why it is not done. It takes a bit longer to do it right.

But things not documented might be thrown out, because no one can figure out how to use them.

Please document things. It need not be polished, but enough that someone who can write can make it usable for others.

Odd Language #68: Punctuation Counts

In http://www.goominet.com/unspeakable-vault/vault/506/ is the sentence, “It was recently given to author Nnedi Okorafor; soon after she discovered that HPL was an (ugly) racist.”

The issue: The name “Nnedi Okorafor” was bolded so the semicolon was much less visible. Without the semicolon, the meaning would change to her discovering HPL’s racism to before she got the award instead of after.

Puzzle #71: Midterms

Midterms are approaching. You are taking five courses. Unfortunately, all five courses’ midterms are in the same week (Monday to Friday).

1) On Monday, Wednesday, and Friday combined, you have four midterms.
2) On Tuesday, Wednesday, and Thursday combined, you have three midterms.
3) On Tuesday and Friday combined, you have three midterms.

How many midterms do you have on each of the days Monday to Friday?

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, October 15, 2014 at noon Pacific Time. I will post the answer shortly after.

Puzzle #69 Solution: Majors

Spoiler Inside: Solution to Puzzle SelectShow