Beyond the answers - interesting background to this quiz

The eye's colour palette is smaller than it looks

The iris, the ring of muscle around the pupil, is the part that can be blue, green, hazel or brown. Colour comes from melanin, the same pigment that tints skin and hair; blue eyes contain very little of it, and the shade we see is largely an effect of how light scatters in the iris. The sclera, the white outer coat, stays white in healthy eyes, while the pupil is simply a gap that appears black because almost no light escapes it.

French Guiana is France, in South America

French Guiana sits on the northeast coast of South America, yet it is not an independent country - it is an overseas department of France, and its currency is the euro. Its status also makes it part of the European Union, with the European Space Agency's launch site at Kourou on its coast. Neighbouring Venezuela uses the bolívar, while the krone belongs to Denmark and Norway.

Gin's grain base and the wider spirits map

Gin is distilled from a neutral grain spirit, which is then flavoured with juniper berries and other botanicals. That grain origin separates it from rum, which is made from sugarcane or its by-products, and from tequila, which is distilled from the blue agave plant in Mexico. The three drinks are a neat illustration of how geography shapes what goes into a bottle.

Concorde's long goodbye

Concorde entered service in 1976 and flew until 2003, when both British Airways and Air France retired their fleets. The aircraft crossed the Atlantic in around three and a half hours at roughly twice the speed of sound, but high fuel consumption, rising maintenance costs and a drop in passenger numbers after a 2000 crash made it uneconomic to keep flying.

Ashgabat and the Karakum setting

Ashgabat is the capital of Turkmenistan, a Central Asian country largely covered by the Karakum Desert. The city is known for its extensive use of white marble on public buildings, a style that has earned it a place in record books. Mary and Turkmenbashi are also Turkmen cities, which makes them plausible but incorrect choices for the capital.