Table of Contents
- Time Limit: 15 minutes to complete the quiz.
- Multiple Choice: Each question has several answer options.
- One Correct Answer: Only one option is correct for each question.
- No Negative Marking: No penalty for incorrect answers.
Class 9 Maths Chapter 1 Real Numbers Quiz Questions
Welcome to Quiz 4 on Class 9 Maths Chapter 1 – Real Numbers! from Class 9 Maths syllabus. This quiz covers number systems, including natural, whole, integers, rational, and irrational numbers. Test your understanding of these concepts and apply your knowledge to different problem-solving scenarios. Sharpen your skills and dive into the world of numbers!
Class 9 Maths Chapter 1 Real Number Of Life Quiz 4
Ques: Between any two numbers, there are _________.
a) Two rational numbers
b) No rational number
c) Infinite rational numbers
d) None of the above
Answer:
C
Infinite rational numbers are present in between any two numbers.
Ques: The sum of odd numbers up to 240 is _____.
a) 11400
b) 12400
c) 13400
d) 14400
Answer:
D
Number of odd numbers up to 240 = 240/2 = 120
Sum of first n odd numbers = n²
n = 120
Required sum = 120² =14400
Ques: Identify a rational number among the following numbers.
a) 2+√2
b) 2√2
c) 0
d) π
Answer:
C
0 is a rational number.
Ques: √11 is greater than √21.
a) True
b) False
Answer:
B
These numbers are irrational numbers as these are not perfect square roots. In order to compare them we will have to first compare them as rational numbers.
(√11)² = √11 × √11 = 11
(√21)² = √21 × √21 = 21
Since 21 > 11 so √21 > √11
Ques: Number line consists of Whole numbers?
a) True
b) False
Answer:
A
Number line consists of Whole numbers
Ques: The product of a non-zero rational and an irrational number is:
a) always irrational
b) always rational
c) rational or irrational
d) one
Answer:
A
The product of a non-zero rational and an irrational number is always irrational. For example:
2×√3
=2√3
Here the product of 2 (rational number) and √3 (irrational number) is an irrational number 2√3.
Ques: Given that 2 is irrational, 5+32 is also an irrational number.
a) True
b) False
Answer:
A
Let us assume, to the contrary that 5+3√2 is rational.
That is, we can find coprime a and b (b≠0) such that 5+3√2=a/b
Therefore,
5−a/b=3√2
⇒√2=5b−a/3b
Since, a and b are integers, we get 5b−a/3b is rational, and so √2 is rational which contradicts the fact that √2 is irrational. So, our assumption was wrong that 5+3√2 is rational.
Hence, we conclude that 5+√32 is irrational.
Ques: Given that √3 is an irrational number, 5+√2 is not an irrational number.
a) True
b) False
Answer:
B
Suppose 5 + 2√3 is a rational number.
Therefore, it can be written in p⁄q form, where p and q are coprime integers.
5 + 2√3 = p⁄q
√3 = p − 5q⁄2q
Since p and q are integers, therefore p − 5q⁄2q must be a rational number.
But this is a contradiction as the LHS is an irrational number.
This suggests that the assumption was wrong.
Hence, 5 + 2√3 is an irrational number.
Ques: Every integer is a rational number
a) True
b) False
Answer:
A
True, because every integer m can be expressed in the form 1 x m , and so it is a rational number.
Ques:
Every rational number is an integer
a) True
b) False
Answer:
B
False, because 35 is not an integer
