Beyond the answers - interesting background to this quiz

When letters did the work of numbers

Roman numerals like CC were the everyday counting system of Europe for well over a thousand years. Each C stands for 100, so CC means 200, and the system builds larger values by adding or subtracting symbols. Its awkwardness with large numbers and arithmetic is one reason positional systems, spread through medieval Europe via Arabic-language mathematics, gradually replaced it.

Samoa's capital and the Pacific crossroads

Apia sits on the island of Upolu and is the capital of Samoa, a Polynesian nation in the South Pacific. It became a significant harbour in the late 19th century, when Britain, Germany and the United States competed for influence over the Samoan islands. Samoa gained independence in 1962, making it one of the first Pacific island nations to do so.

The Indus and a cradle of civilisation

The Indus River rises in the Tibetan plateau and flows through China before running mostly through Pakistan to the Arabian Sea. Along its lower course grew the Indus Valley Civilisation, whose planned cities such as Mohenjo-daro and Harappa flourished thousands of years ago. The river remains a lifeline for agriculture in an otherwise arid region.

One date, two very different headlines

In 1969, Neil Armstrong became the first person to walk on the Moon during the Apollo 11 mission, a moment watched by millions on television. Four years earlier, in 1963, President John F. Kennedy was assassinated in Dallas, Texas. Placing these events side by side shows how tightly the space race and Cold War politics were woven together.

Pyongyang and the chemistry of symbols

Pyongyang, the capital of North Korea, lies in East Asia. The city is one of the oldest continuously inhabited settlements on the Korean peninsula. Neodymium, symbol Nd, is a rare-earth metal used in powerful magnets found in headphones, hard drives and wind turbines, a reminder that a single chemical symbol can connect to everyday technology.