Competition rules:

1. To be eligible to win, you must provide correct answers to the first nine questions. The winner will then be decided based on their answer to the tiebreaker question at the end. The three most creative entries will each win a pair of tickets to the festival. If there are not enough entries that have all the first nine entries correct, winners will be chosen from the entries with the highest number of correct answers.

2. The winners will be contacted personally by email within seven days of the closing date. If the winner does not respond to this email within seven days, the prizes will be re-allocated to a runner up.

3. The competition is open to all entrants in all countries, except employees and their families of WaterAid, Greenpeace or Oxfam.

4. You must provide your name, telephone number and e-mail address if you wish to enter this competition. We will not publish your personal details and will not use them beyond administering this competition, unless you opt in to hear more from us.

5. Only one entry will be accepted per person. Multiple email addresses are not allowed.

6. The judges' decision is final in every situation including any not covered above, and no correspondence will be entered into. No cash alternatives and no substitute prizes will be offered.

7. The competition closes at noon (BST) on Saturday 2nd May 2009.

8. We will not accept any responsibility for late or lost entries due to problems with the online submission process. Proof of sending is not proof of receipt.

9. Entrants must supply full details as required above, and comply with all rules to be eligible for the prizes. No responsibility is accepted for ineligible entries or entries made fraudulently.

10. A list of winners will be posted after the competition deadline at www.leavenotrace.org/winners

11. The competition is only open to those aged 18 or over. Anyone under 18 who enters the competition will be deemed ineligible.

12. Entrants will be deemed to have accepted these rules and to agree to be bound by them when entering this competition.

13. This competition is administered by Greenpeace, Oxfam and WaterAid.