Passengers stranded as Qatar Airways suspends flights to Saudi Arabia

What is the primary focus of the introduction section regarding the number 21?

• Cultural references to 21

• Mathematical operations involving 21

• The significance and basic concept of 21

• The history of the number 21

In which context is the number 21 commonly used?

• As a unit of measurement

• In binary code

• In card games like Blackjack

• As a prime number

Which of the following is an example of how 21 is applied?

• As a base in logarithms

• In the Fibonacci sequence

• As a factor of 100

• In legal age restrictions

What is a key takeaway from the conclusion about the number 21?

• 21 is a universally prime number

• 21 has limited applications

• 21 is significant in various fields

• 21 is only important in mathematics

Which section would you find a summary of the key points discussed about 21?

• Introduction to 21

• Examples and Applications of 21

• Conclusion on 21

• None of the above