A) Natural number
B) Rational number
C) Irrational number
D) An integer
View Answer
C) Irrational number
Explanation:We are given the number:
Step-by-step shortcut: is irrationalThe reciprocal of an irrational number is also irrational
(unless it simplifies to a rational, which does not)
Final Answer: Irrational number
7) If 2x = 82 then x=
A) 2
B) 4
C) 6
D) 8
View Answer
C) 6
Explanation:We are given:
2x = 82
Shortcut method:
Rewrite 8 as a power of 2:
8 = 23 ⇒ 82 = (23)2 = 26
So,
2x = 26 ⇒ x = 6
8) A={C,O,V,I,D,19,2020}, B={C,O,V,I,D,19,2021} then B-A=
A) (2020)
B) (2021)
C) (2020, 2021)
D) (C,O,V,I,D,19,2020, 2021)
View Answer
B) (2021)
Explanation:We are given two sets:
A = {C, O, V, I, D, 19, 2020}
B = {C, O, V, I, D, 19, 2021}
We are asked to find B − A, which means the elements that are in Bbut not in A.
Shortcut:
Compare both sets:
Common elements: C, O, V, I, D, 19Bhas 2021which Adoes not.
So:
Final Answer: (2021)
9) Find the value of logo.1 0.01
A) 1
B) 2
C) 3
D) 4
View Answer
B) 2
Explanation:We are asked to find:
Shortcut Method:
Write both numbers as powers of 10:
So the expression becomes:
Use change of base formula:
10) The roots of x2+x-6=0 are
A) 2,-3
B) -2,3
C) 2,3
D) -2,-3
View Answer
A) 2,-3
Explanation:We are given the quadratic equation:
Shortcut Method: Splitting the middle term
We need two numbers that multiply to -6and add to +1(coefficient of x):
Numbers: 3 and -2
So we factor:
x2 + 3x – 2x – 6 = 0
x(x + 3) -2(x + 3) = 0
(x – 2)(x + 3) = 0
Roots are: x = 2, -3