question_answer 1)

Give three pairs of prime numbers whose difference is 2. [Remark Two prime numbers whose difference is 2 are called twin primes].

Answer:

                Three pairs of prime numbers whose difference is 2 are as follows: (i) 5, 7                    i.e. 7 ? 5 = 2 (ii) 11, 13              i.e. 13 ? 11 = 2 (iii) 17, 19             i.e. 19 ? 17 = 2