This task involves creating questions from a given passage that involve some kind of complex reasoning (including numerical reasoning).
The generated questions must require looking at more than one part of the passage to answer. Try to use a variety of reasoning types in your questions (some of the sample reasoning types are illustrated in the 'positive examples' field) and also have a variety of answer types (spans, numbers, dates). A span is a continuous phrase taken directly from the passage or question. In such questions, the answer spans are recommended to be five words. Questions with answer type "number", are expected to start with "How many". For instance, "How long did an event last?" can be phrased as "How many years did an event last?". To increase diversity, try to create more questions for which the answer will be multiple spans. Please create questions that require AT LEAST 2 arithmetic operations as illustrated in the 'positive examples' field. You are encouraged to try DIFFERENT COMBINATIONS of operations and not just limit to the combinations shown in those examples. The more challenging questions you create, the better it is.
Q: Passage: Until the mid-20th century most of Yucatan's contact with the outside world was by sea; trade with the US and Cuba, as well as Europe and other Caribbean islands, was more significant than that with the rest of Mexico. In the 1950s Yucatan was linked to the rest of Mexico by railway, followed by highway in the 1960s, ending the region's comparative isolation. Today Yucatan still demonstrates a unique culture from the rest of Mexico, including its own style of food. Commercial jet airplanes began arriving in Merida in the 1960s, and additional international airports were built first in Cozumel and then in the new planned resort community of Cancun in the 1980s, making tourism a major force in the economy of the Yucatan Peninsula. The first Maya governor of Yucatan, Francisco Luna Kan, was elected in 1976. Today, the Yucatan Peninsula is a major tourism destination, as well as home to one of the largest indigenous populations in Mexico, the Maya people.
A:
How many commercial airports were mentioned?