CISRA Puzzle Competition 2007 - Frequently Asked Questions

This is the archive of the 2007 Puzzle Competition. Please visit the current competition site for information about the latest Puzzle Competition.


My five friends and I want to form a team. Can we have a team of six?

The maximum team size is four. The best thing to do is to form two teams of three, and perhaps try to recruit other members to bring your teams up to four. Any people who help a team beyond the registered four members are unofficial helpers. If your team is eligible and wins a prize, only the registered members will receive the prizes. Unofficial helpers may not contribute to more than one team.

We started a team of two, but we've found two more people who want to help. Can they join our team?

Yes, they can. Remember that they can't already be on another team, and if they are not Australian students, your team will be ineligible for prizes. Use the form on the bottom of the registration page to add team members.

I want to join a team, but I've already registered by myself or in a smaller team. What should I do?

E-mail us ( to request deactivation of your team before Puzzle Week begins. After we confirm that your team has been deactivated, you will be free to join another team. Do not attempt to join a team while still on another team - you will disqualify both teams. Once Puzzle Week begins, nobody may change teams.

I created a team but realised I typed in the wrong details. What should I do?

E-mail us to let us know, and we'll fix it for you. Don't create another team, or you risk disqualification.

We just found out about the competition, but a bunch of teams already have 20 points! How do we stand a chance if we sign up late?

The Group 1 puzzles were released several weeks before Puzzle Week, but they are still worth 5 points each up until 9:00am Tuesday 17 April AEST. If you can solve them by then, you'll have 20 points too, and can take the lead by being the first to solve a Group 2 puzzle.

The Puzzles

Is there a meta-puzzle?

Some puzzle contests have meta-puzzles which require the answers to several other puzzles to solve. There is no such meta-puzzle in the CISRA Puzzle Competition. There are just 20 puzzles, in five Groups of four.

This puzzle is impossible! Help?

Please check the puzzle solving guide, which contains all the instructions and assistance we can give you on how to solve the puzzles.

How did you decide on the difficulty levels for each puzzle?

The difficulties were chosen based on how many steps there are to solve the puzzle, and how complex, lateral, and time-consuming each step is. Different people are good at different things, and some people won't get stuck at all on a "Hard" puzzle, while others may find an "Easy" puzzle challenging, so the difficulties should only be used as a general guide.

I think there's a mistake in this puzzle!

Please e-mail us if you think you've found a mistake. We will tell you whether or not it is a mistake. (If it is, we'll also correct the puzzle.)

Will we get to see the answers to the puzzles after the competition?

Yes. We will release full worked solutions to each puzzle at the end of the competition.

Why do you only allow 100 answer attempts per puzzle Group?

Answer attempts are limited to discourage teams from simply guessing answers. This strategy will almost certainly fail anyway - you're better off trying to solve the puzzle completely than guessing what the answer might be. If you work through the puzzles as intended, you're unlikely to need more than 10 answer attempts per puzzle Group.

What are the medals? How do we get them?

The medals are minor rewards given to teams who solve all the puzzles in a Group. There are different medals for each Group, plus bonus "rank" ribbons which depend on how many hints the team needed to complete the Group. These medals are simply graphical extras that teams might aspire to collect; they do not affect the scoring and ranking of teams in any way.


How can we contact you?

If you have questions about the Puzzle Competition, send e-mail to This address is only for administrative and technical issues. We will not give out hints or clues for any puzzles, and asking for them may be grounds for disqualification.

Why are prizes only available to Australian students?

CISRA is interested in bright graduates for employment opportunities, and is located in Australia. The puzzle competition is an adjunct to CISRA's Australian universities graduate recruitment programme.

Okay, so why is anyone allowed to enter?

We know many people enjoy the mental stimulation of solving new and interesting puzzles - some of us work here at CISRA! Organised puzzle contests like this are few and far between, so we wanted to give all puzzle fans the chance to test their mettle.

I heard about puzzle postcards. What's the story?

Four different puzzle postcards are being used to promote this competition in Australian universities. They contain the puzzles from Group 1. (Collect the set!) There are no postcards for the remaining puzzles. You do not need any of the postcards to participate in or win the competition.

Why did you release four puzzles at the start of March, when the other 16 puzzles will be released during a single week in April?

The first four puzzles were printed on postcards, and distributed throughout Australian universities to promote CISRA and the competition. The same four puzzles are available on the puzzle site in advance, so that the people who take the postcards won't have an unfair head start.


CISRA sounds like a good place to work. Where can I find out more?

CISRA is Canon Information Systems Research Australia, a leading research and development centre for Canon. We employ people with backgrounds in computer science, physics, software engineering, mathematics, and/or image processing. Students in these fields should check our Graduate Recruitment site, while others should look at the main Jobsite.

If I do poorly in the puzzle competition, will I be less likely to be hired by CISRA as a result? If I do well, will I be more likely to be hired?

No. The purpose of this competition is to promote and publicise CISRA, not to grade job applicants. Details of individual participants and their performance in the competition will not be given to CISRA's hiring department.