CBSE - Number Systems

1 Number Systems 

If 2 is a root of the equation x² + bx + 12 = 0 and the equation x²  + bx + q = 0 has equal roots, then q = 

(1)  8  
(2)  – 8
(3)  16
(4)  – 16 

 

2 Number Systems 

Sum of the roots of the equation x⁴ - 3(2^{x + 3}) + 128 = 0, is:

(1) 0 
(2) 7
(3) 5 
(4) 8

3 Number Systems 

The number obtained by adding 12 to a natural number is 160 times of the multiplicative inverse of the natural number. Find the number.

1) 20
2) 16
3) 12
4) 8

4 Number Systems 

The absolute value of an integer x is represented by :

1) [x]
2) {x} 
3) (x)
4) | x |  

5 Number Systems 

If an integer a is less than integer b, then :

1) a lies on the right of b on the number line
2) b lies on the right of a on the number line
3) a lies on the left of b on the number line
4) Both (2) & (3)

6 Number Systems 

If   , then the value of x² + 2x + 3 is:

(1) 3 
(2) 0 
(3) 4 
(d) 1

7 Number Systems 

What is the largest integer that is a divisor of (n +1) (n+3) (n+5) (n+7) (n+9) for all positive even integers n? 

1) 3
2) 5 
3) 11
4) 15 

8 Number Systems 

What is the smallest number which when increased by 5 is completely divisible by 8, 11 and 24? . 

1) 259
2) 355
3) 255
4) none

9 Number Systems 

If 3 is the least prime factor of number a and 7 is the least prime factor of number b, then the least prime factor of a + b is :

(1)  2  
(2)  3
(3)  5
(4)  10

10 Number Systems 

If x, y, z are positive real numbers and a, b, c are rational numbers, then the value of    is :

(1)  –1  
(2)  0 
(3)  1 
(4)  none of these