This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
Example: Passage: The French and Indian War (17541763) was the North American theater of the worldwide Seven Years' War. The war was fought between the colonies of British America and New France, with both sides supported by military units from their parent countries of Great Britain and France, as well as Native American allies. At the start of the war, the French North American colonies had a population of roughly 60,000 European settlers, compared with 2 million in the British North American colonies. The outnumbered French particularly depended on the Indians. Long in conflict, the metropole nations declared war on each other in 1756, escalating the war from a regional affair into an intercontinental conflict. Question: When was the French and Indian War?
Example solution: 1754-1763
Example explanation: It is a common convention to write (start year-end year) beside a historical event to understand when the event happened. We can observe a similar notation from the passage to conclude that the French and Indian War happened during 17541763. Therefore, the answer is 17541763.

Problem: Passage: Red is the color at the end of the spectrum of visible light next to orange and opposite violet. Red color has a predominant light wavelength of roughly 620740 nanometres. Red is one of the additive primary colors of visible light, along with green and blue, which in Red Green Blue (RGB) color systems are combined to create all the colors on a computer monitor or television screen. Red is also one of the subtractive primary colors, along with yellow and blue, of the RYB color space and traditional color wheel used by painters and artists. Question: How many nanometres does red have?
Solution: roughly 620740