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\ 07-Nov-2024 Bharat Arora Proof-8 Reader’s Sign _______________________ Date __________

Chapter assessment
A. Choose the correct option.

1. How many more prime numbers are there between 16 and 80 than between 90 and 100?
(a) 14 (b) 7 (c) 15 (d) 16
2. Which of the following statements is not true?

(a) The HCF of two distinct prime numbers is 1.
(b) The HCF of two co-prime numbers is 1.
(c) The HCF of two consecutive even numbers is 2.
(d) The HCF of an even and an odd number is even.

3. The number of distinct prime factors of the largest 4-digit number is
(a) 2 (b) 3 (c) 5 (d) 11
4. The number of distinct prime factors of the smallest 5-digit number is
(a) 2 (b) 4 (c) 6 (d) 8

5. The greatest number which always divides the product of the predecessor and successor of an odd
natural number other than 1, is

(a) 6 (b) 4 (c) 16 (d) 8
6. Which of the following numbers is divisible by 11?
(a) 1011011 (b) 1111111 (c) 22222222 (d) 3333333
7. If the LCM of two numbers is 180, then which of the following cannot be the HCF of the numbers?
(a) 45 (b) 60 (c) 75 (d) 90

B. Assertion and Reason Type Questions.
In the following question, a statement of Assertion (A) is followed by a statement of Reason (R).
Choose the correct option.
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true but Reason (R) is false.
(d) Assertion (A) is false but Reason (R) is true.
1. Assertion (A): The factors of 16 are 1, 2, 4, 8, 16.
Reason (R): The factor of a number is an exact divisor of the number.
2. Assertion (A): 4809 is divisible by 3.
Reason (R): A number is divisible by 2 if it has any of the digits 0, 2, 4, 6 or 8 in its ones place.
3. Assertion (A): The HCF of 20, 24 and 32 is 2.
Reason (R): The Highest Common Factor (HCF) of two or more given numbers is the highest (or
greatest) of their common factors.
C. Fill in the blanks.
1. The sum of the prime factors of 1729 is .....................

2. The number of common prime factors of 75, 60, and 105 is .....................
3. The LCM of the two co-prime is equal to .................... of the numbers.

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