ERJ Brainteaser: December
5 Dec 2025
Each month, ERJ sets a weekly brainteaser, with questions of varying degrees of difficulty. Readers supplying the most accurate (and stylish) answers are then considered for the prestigious Brainiac of the Month and now Brainiac of the Year titles.
Question 2: Square deal
First square = 5, second square = ?
Email your answer: correct replies on Friday.
Find the rubber connection in: Egypt, Laos, Austria, Spain, Thailand, Oman, Mexico, Ecuador, Rwanda.
Answer: We do try to avoid sending readers on a ‘wild goose chase’, so apologies if that was the case for anyone this week. Many thanks for all the imaginative, alternative ideas, but the solution here is simply that the first letter of each country-name spell the word ELASTOMER. Very well done to: Amparo Botella, responsable de Compras y Calidad, Ismael Quesada SA, Elche, Alicante, Spain; Antonella Pagliarulo, product development manager, performance polymer solutions, Thomas Swan & Co. Ltd, Consett, County Durham, UK; John Woods, consultant, Germany; Andrew Knox, Rubbond International, Ohé en Laak, The Netherlands; Kamila Staszewska, R&D / quality lead, Abcon Industrial Products Ltd, Cootehill, Co. Cavan, Ireland; John Bowen BSc [Hons], CEng, MIMMM, consultant, Bromsgrove, UK; Andy Longdon, technical sales manager, Ceetak Ltd, Bedford UK; Sudi Sudarshan, principal consultant, Global Mobility Strategies, USA; and everyone else who had a go.
New teaser on Monday.
