Beyond the answers - interesting background to this quiz

A currency named after what it once was

Brazil's currency, the real, takes its name from the Portuguese word for "royal" and connects to the country's colonial past, when the term referred to gold and silver coins. The modern real was introduced in 1994 as part of a broader economic stabilisation effort, replacing a currency that had been eroded by extreme inflation. Its plural, reais, is one of those small language details that trips up visitors.

Silver's symbol hides a Latin past

The chemical symbol for silver, Ag, comes from the Latin word argentum, which also gave us the name of Argentina. That is no coincidence: the country's name is linked to the silver that Spanish explorers hoped to find in the region. Silver sits alongside gold and copper as one of the metals known and used since ancient times, which is why it carries a symbol rooted in Latin rather than a modern abbreviation.

Sunlight and the vitamin your body builds itself

Vitamin D is unusual among vitamins because the body can produce it, provided the skin gets enough sunlight. When ultraviolet light hits the skin, it triggers a reaction that helps convert a form of cholesterol into vitamin D. This explains why deficiency is more common in places with long, dark winters, and why diet alone does not always cover the need.

Tidal power and the pull of the moon

Tidal power relies on the predictable rise and fall of the sea, driven mainly by the gravitational pull of the moon and, to a lesser extent, the sun. South Korea has become a leading producer, thanks in part to its large tidal range and suitable coastal geography. Unlike wind or solar, tidal energy is remarkably regular, though building the infrastructure is costly and can affect local marine environments.

Two countries, two very different currency stories

The Netherlands uses the euro, having replaced its long-standing guilder when it joined the euro area. Brazil, by contrast, kept its own currency and navigated its own path through monetary reform. Comparing the two is a neat reminder that currency choices reflect history, politics and economics rather than any single global rule.