Well done to everyone who cracked Challenges 5A and 5B, this was a tough round and the top of the overall leaderboard shows it. We are down to just 16 sharing top honours for the competition. Of course if they all slip up there is still room for people lower down to steal the title. Anyway, here are the winners of the Challenge 5A prizes: The book prize goes to Chatham Grammar School For Boys for the efforts of Short Stuff, (Cryptus, Zacsafus, Mr Biggles and Banksy), while the following teams each win one of the £25 cheques: Kolobok from Dame Alice Owen's School Tree Huggers from Wootton Bassett Anna, Iona, Laura, Giulia, Alisha, Jeannine and Tianna from Queen's Gate Patrick and Andrew from Woodbridge School Mohamed Husein, Mahmood Husein, Douglas Benn, Jawad Arshad, Matt Mitchell and from Walton High School Ed from The Gryphon School Captain Nosh from Barton Peveril Helen Wickins from Alcester Grammar School