A set of incorrect answers were previously published on this page. This was due to a technical mistake, and will not affect the result of the competition. The winners will be notified by email on June 30th.

The correct correct answers are listed below. Please accept the BBC's apologies for any confusion this error may have caused.

Question.

1. a
2. b
3. a
4. c
5. c
6. b
7. c
8. b
9. b
10. a
11. c
12. a
13. b
14. c
15. a