Race Institute

#38, Burkit Road,

Opposite to bus terminal,

Thyagaraya Nagar

Chennai - 600 017.

Phone:

044-64563030

044-42660776

Mobile:

9043303030

Contact Person:

Bharath Seeman

Number System

 

1.Which of the following is prime numbers?

A. 149

B. 437

C. 319

D. 197

2.Which of the following is not prime number?

A. 149

B. 137

C. 319

D. 811

3.A prime number N, in the range 10 to 50, remains unchanged when its digits are reversed. The square of such a number is: [CDS 2002]

A. 1936

B. 1089

C. 484

D. 121

4.For what value of n are prime numbers? [CDS 2006]

A. 3

B. 5

C. 2

D. 1

5.What are the prime factors of 70?

A. (2, 3, 5)

B. (3, 5, 7)

C. (2, 5, 7)

D. (11, 7, 2)

6.The prime factors of 15015 are: [CDS 1997]

A. 3, 5, 7, 11, 37

B. 3, 5, 11, 13, 37

C. 3, 5, 7, 13, 37

D. 3, 5, 7, 11, 13

7.The numbers of prime factors in the following expression,

A. 54

B. 64

C. 71

D. 31

8.Three numbers which are co-prime to one another are such that the product of the first two is 77 and last two is143. The sum of the three numbers is: [SSC Grad. 2003]

A. 15

B. 27

C. 31

D. 39

9.The sum of the digits of a two –digit number isof the difference between the number and the number obtained by interchanging the position of the digits. What is definitely the difference between the digits of the number? [Bank 2000]

A. 5

B. 9

C. 7

D. data inadequate

10.There are four prime numbers written is ascending order. The product of the first three is 385 and that of the last three is 1001. Find the first number.

A. 5

B. 7

C. 11

D. 17