a2zinterviews

6.	The least prime number is
	A.  0
	B.  1
	C.  2
	D.  3

Solution

The least prime number is 2.

7.	What is the total number of prime numbers less than 70?
	A.  17
	B.  18
	C.  19
	D.  20

Solution

Prime numbers less than 70 are =12. 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,and 67 Their number is 19.

8.	The total number of even prime number is
	A.  0
	B.  1
	C.  2
	D.  None of these

Solution

There is only one prime number, namely 2.

9.	Find the sum of prime numbers lying between 60 and 75.
	A.  199
	B.  201
	C.  211
	D.  272

Solution

Required sum =61 + 67 + 71 + 73 = 272.

10.	The smallest value of n, for which 2n+1 is not a prime number, is
	A.  3
	B.  4
	C.  5
	D.  None of these

Solution

(2×1 + 1) = 3. (2×2 + 1) = 5. (2×3 + 1) = 7. (2×4 + 1) = 9. which is not prime , n=4.