Prime Numbers

15 Points Per Correct Answer - No time limit  

1. A prime number is a natural number which can be divided by two different divisors (namely 1 and the prime number itself) without remainders. Which of the followings is/are prime number(s)? Both 1 0 Neither

2. Which of the following is the greatest 3-digit prime? 997 998 999 996

3. An integer that is greater or equal to 2 is categorized into 2 groups. The first group is the prime number. These prime numbers are the basic building blocks for the second group of number, which is known as? The complex number The composite number The rational number The irrational number

4. Which of the following statements is false? An odd integer may be a prime number. In the set of integers from 1 to 1000000, there are more composite numbers than prime numbers. Any integer greater than 5 that ends with a 5 is not a prime number. An even integer is definitely not a prime number.

5. The Sieve of Eratosthenes is one of the methods to determine whether a given integer is a prime number or not. There exists another method, which is called? The Sieve of Atkin The Sieve of Fermat The Sieve of Leibniz The Sieve of Gauss

6. Many great mathematicians proved that there is an infinite number of prime numbers. Which of the followings is NOT one of them? Euclid Harry Furstenberg Euler Isaac Newton

7. Any prime number that can be expressed in the form of 2^(2^n) + 1 is called a Fermat prime. On the other hand, what is the name given to a prime number that can be expressed in the form of 2^n – 1, where n is any prime number? A Sophie Germain Prime A Mersenne prime A Wilson prime A Wagstaff prime

8. The largest known prime number so far (July 2007) is 2^32582657 – 1, which contains approximately 9.8 million digits. Which organization is offering a USD 100,000 reward to the person or group who discovers a prime number which has more than 10 million digits? Great Internet Mersenne Prime Search Electronic Frontier Foundation Electronic Mersenne Foundation Great Internet Frontier Prime Search

9. A very famous theorem can be used to estimate how many prime numbers are there between 1 and x by using the formula x/In x. Which theorem is it? The Proth Theorem The Dirichlet Theorem The Prime Number Theorem The Fermat Theorem

10. Prime numbers are used in cryptography algorithms, which are used in the field of military and banking. True False