How many 55-gram bars of chocolate can a 50-centimetre spaghetti bridge support? This tricky question was posed by the British Education Festival's spaghetti-bridge building competition. The answer was 47 bars, 100 times the weight of the bridge, which was created by three secondary school students. The spaghetti engineers were Form Six students Lam Hung, Hung Mat-lang and Hsu Man-tai of Pui Ying Secondary School, Hong Kong. They built a bridge weighing just 25.72 g, which could hold more than 2.5 kilograms of chocolate. However, this impressive achievement did not make them winners. Instead bridge builders from City University (CityU) and Shatin Government Secondary School beat all the other entries by being the lightest, but still able to support at least 12 bars of chocolate weighing a total 660 g. The competition was run by the University of Leeds' School of Civil Engineering. According to the university's Professor of Civil Engineering, Donald Dalton, the competition required a combination of lateral thinking and flair. During the two days of competition, Professor Dalton and bridge architects from the university gave guidance to the students. Bridges were subjected to loading tests, using a sophisticated electronic scale capable of giving measurements to within 0.01 g. The winner of the over-17 age group was CityU first year applied physics student Yau Ka-wing. He built a 50 cm bridge weighing just 15.93 g, which successfully supported 16 bars (880 g) of chocolate. He shared his victory with his classmates. Ka-wing and four fellow physics students applied their university learning by carrying out experiments on five brands of spaghetti. Classmate Cliff Chu Kam-keung said: 'We looked for the lightest, most solid but elastic one.' Using their number one choice of spaghetti, they erected a trapezoid bridge at first attempt in the competition. Ka-wing said 'patience' was the key. 'We waited for the glue to dry . . . and we had to cope with our fingers getting stuck together sometimes,' he said. Ko Oi-tsz, Lee Hoi-lam and Jocelyn Ony Lai, Form Three students from Shatin Government School, built a 25.12 g, 40 cm bridge, which bore the weight of 14 bars (770 g). They won the under-17 category. Oi-Tsz said girls were probably better at building spaghetti bridges because the work was 'fine and sophisticated', requiring extra care.