CBSE Class 6 Maths Chapter 5: Prime Time — Assertion & Reason
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The following Assertion and Reason questions are based on Chapter 5: Prime Time from the NCERT Class 6 Mathematics textbook. Each question has four options - read both the Assertion (A) and Reason (R) carefully before selecting your answer.
How to attempt Assertion & Reason questions:
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Assertion & Reason Questions
1
Assertion (A): A prime number has exactly two positive factors.
Reason (R): Its only positive factors are 1 and the number itself.
Reason (R): Its only positive factors are 1 and the number itself.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. The factor definition directly explains primality.
2
Assertion (A): A prime number has exactly two positive factors.
Reason (R): The number 2 is even.
Reason (R): The number 2 is even.
Answer: (b)
Both A and R are true, but R is NOT the correct explanation of A. Both statements are true, but the second statement does not explain the first.
3
Assertion (A): A prime number has exactly two positive factors.
Reason (R): Every prime number has three factors.
Reason (R): Every prime number has three factors.
Answer: (c)
A is true, but R is false. A prime has two factors, not three.
4
Assertion (A): The number 1 is prime.
Reason (R): Its only positive factors are 1 and the number itself.
Reason (R): Its only positive factors are 1 and the number itself.
Answer: (d)
A is false, but R is true. One has only one positive factor.
5
Assertion (A): A composite number has more than two positive factors.
Reason (R): It can be expressed as a product of smaller positive integers other than 1 and itself.
Reason (R): It can be expressed as a product of smaller positive integers other than 1 and itself.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. A nontrivial factorisation supplies extra factors.
6
Assertion (A): A composite number has more than two positive factors.
Reason (R): The number 2 is the only even prime.
Reason (R): The number 2 is the only even prime.
Answer: (b)
Both A and R are true, but R is NOT the correct explanation of A. Both statements are true, but the second statement does not explain the first.
7
Assertion (A): A composite number has more than two positive factors.
Reason (R): Every composite number is odd.
Reason (R): Every composite number is odd.
Answer: (c)
A is true, but R is false. Composite numbers may be even or odd.
8
Assertion (A): The number 17 is composite.
Reason (R): It can be expressed as a product of smaller positive integers other than 1 and itself.
Reason (R): It can be expressed as a product of smaller positive integers other than 1 and itself.
Answer: (d)
A is false, but R is true. Seventeen has only factors 1 and 17.
9
Assertion (A): Two numbers are coprime when their only common positive factor is 1.
Reason (R): Their HCF is 1.
Reason (R): Their HCF is 1.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. HCF 1 is equivalent to the definition.
10
Assertion (A): Two numbers are coprime when their only common positive factor is 1.
Reason (R): Consecutive integers differ by one.
Reason (R): Consecutive integers differ by one.
Answer: (b)
Both A and R are true, but R is NOT the correct explanation of A. Both statements are true, but the second statement does not explain the first.
11
Assertion (A): Two numbers are coprime when their only common positive factor is 1.
Reason (R): Both numbers must individually be prime.
Reason (R): Both numbers must individually be prime.
Answer: (c)
A is true, but R is false. Composite numbers can be coprime to one another.
12
Assertion (A): The numbers 8 and 15 are not coprime.
Reason (R): Their HCF is 1.
Reason (R): Their HCF is 1.
Answer: (d)
A is false, but R is true. Eight and fifteen share no factor above 1.
13
Assertion (A): Prime factorisation expresses a number as a product of primes.
Reason (R): The fundamental building blocks in the factor tree are prime numbers.
Reason (R): The fundamental building blocks in the factor tree are prime numbers.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Continuing until all leaves are prime gives the representation.
14
Assertion (A): Prime factorisation expresses a number as a product of primes.
Reason (R): Multiples of 5 end in 0 or 5.
Reason (R): Multiples of 5 end in 0 or 5.
Answer: (b)
Both A and R are true, but R is NOT the correct explanation of A. Both statements are true, but the second statement does not explain the first.
15
Assertion (A): Prime factorisation expresses a number as a product of primes.
Reason (R): A prime factorisation may end with composite factors.
Reason (R): A prime factorisation may end with composite factors.
Answer: (c)
A is true, but R is false. Composite leaves must be factored further.
16
Assertion (A): The prime factorisation of 12 is 2 x 6.
Reason (R): The fundamental building blocks in the factor tree are prime numbers.
Reason (R): The fundamental building blocks in the factor tree are prime numbers.
Answer: (d)
A is false, but R is true. The complete factorisation is 2 x 2 x 3.
17
Assertion (A): A decimal number is divisible by 3 when its digit sum is divisible by 3.
Reason (R): Powers of 10 leave remainder 1 upon division by 3.
Reason (R): Powers of 10 leave remainder 1 upon division by 3.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Place value makes the number congruent to its digit sum modulo 3.
18
Assertion (A): A decimal number is divisible by 3 when its digit sum is divisible by 3.
Reason (R): A number ending in 0 is divisible by 10.
Reason (R): A number ending in 0 is divisible by 10.
Answer: (b)
Both A and R are true, but R is NOT the correct explanation of A. Both statements are true, but the second statement does not explain the first.
19
Assertion (A): A decimal number is divisible by 3 when its digit sum is divisible by 3.
Reason (R): Only the final digit determines divisibility by 3.
Reason (R): Only the final digit determines divisibility by 3.
Answer: (c)
A is true, but R is false. All digits contribute to the test.
20
Assertion (A): The number 124 is divisible by 3.
Reason (R): Powers of 10 leave remainder 1 upon division by 3.
Reason (R): Powers of 10 leave remainder 1 upon division by 3.
Answer: (d)
A is false, but R is true. Its digit sum is 7, so 124 is not divisible by 3.
❓ Frequently Asked Questions
What is covered in CBSE Class 6 Maths Chapter 5 Prime Time?
This chapter covers all key topics from Prime Time as per CBSE 2026-27 syllabus.
Is this Assertion & Reason useful for CBSE board exams?
Yes, designed for CBSE Class 6 board exam preparation covering the complete syllabus.
Are these CBSE Class 6 Maths Assertion & Reason updated for 2026-27?
Yes, all content at eBookPublisher is updated as per the latest 2026-27 CBSE syllabus.
How many chapters are in CBSE Class 6 Maths?
All chapters of CBSE Class 6 Maths are covered at eBookPublisher with free Assertion & Reason for each chapter.
Can I study Prime Time online for free?
Yes, complete Assertion & Reason for Prime Time is available free at eBookPublisher. Study online directly — no download needed.
Where can I get a complete Assertion & Reason book for CBSE Class 6 Maths?
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