Beyond the answers - interesting background to this quiz

The bay that outranks the Gulf of Mexico

The Bay of Bengal is the largest bay on Earth, stretching between India, Bangladesh, Myanmar and Sri Lanka. Its shape matters: the bay funnels the monsoon winds that dictate farming seasons across South Asia, and the rivers flowing into it, including the Ganges and Brahmaputra, carry enormous amounts of sediment. That sediment has built up over millennia to form the world's largest submarine fan, a vast underwater deposit known as the Bengal Fan.

Why Japan records so many earthquakes

Japan sits where four tectonic plates meet, which is why it experiences more earthquakes than any other country. The constant grinding and slipping along these boundaries also explains the country's volcanoes and hot springs. Japanese engineers have responded with some of the most advanced earthquake-resistant building techniques in the world, and the country's early warning systems can send alerts to phones seconds before shaking begins.

Frank Herbert and the desert planet

Frank Herbert is best known for Dune, published in 1965, a novel set on a desert world where water is the most precious resource. Herbert researched desert ecology and spent years developing the book before it found a publisher. Dune went on to win major science fiction awards and is widely considered one of the best-selling science fiction novels ever written, with film and television adaptations continuing to introduce new audiences to Arrakis.

A quiet corner of the periodic table

Chlorine takes its symbol, Cl, from its name, but its story is less peaceful than it sounds. The element is a yellowish-green gas at room temperature, and its name comes from the Greek word for "pale green". It is used to disinfect drinking water and swimming pools, and it also appears in table salt, where it bonds with sodium. The symbol C, by contrast, belongs to carbon, and Cr to chromium, which is why chemistry students learn to read symbols carefully.

A number with a tidy answer

The square root of 36 is 6, a fact that becomes obvious once you notice that 6 multiplied by itself gives 36. Perfect squares like this one were studied by ancient mathematicians, and the square root symbol itself has a long history in European mathematics. The wrong options in the quiz are not random: 1296 is 36 squared, and 144 is 12 squared, two numbers that often trip up anyone reading the question too quickly.