NCERT Class 6 Math Exercise 3.2 Solution of Chapter 3 Playing with Numbers with explanation. Here we provide Class 6 Maths all Chapters in Hindi for cbse, HBSE, Mp Board, UP Board and some other boards.
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NCERT Class 6 Maths Chapter 3 Playing with Numbers Exercise 3.2 Solution in english Medium.
Class 6 Math Chapter 3 Exercise 3.2 Solution
Q 1. What is the sum of any two
A. Odd numbers?
B. Even numbers?
Ans.
A. Sum of any two odd numbers is always even.
Example : 3+5 = 8,
11+13 = 24
B. Sum of any two even numbers is always even.
Example : 2 + 4 = 6,
4 + 10 = 14
Q.2. State whether the following statements are True or False?
A. The sum of three odd numbers is even.
Ans. False. The sum of three odd numbers is odd.
Example : 1 + 3 + 5 = 9,
3+5+7 = 15
B. The sum of two odd numbers and one even number is even.
Ans. True. The sum of two odd numbers and one ever number is even.
Example : 1+3+4=8,
3+5+10=18
C. The product of three odd numbers is odd.
Ans. True. The product of three odd numbers is odd.
Example : 1×3×5 = 15.
3×5×9 =135
D. If an even number is divided by 2, the quotient is always odd.
Ans. False. If an even number is divided by 2, the quotient is even.
Example : 4÷2 = 2
E. All prime numbers are odd.
Ans. False.
2 is the only prime number is not odd.
F. Prime numbers do not have any factors.
Ans. False.
Since 1 and number itself are the two factors of any prime number.
G. Sum of two prime numbers is always even.
Ans. False. The sum of two prime numbers can be even or odd.
Example : 2+3 = 5,
3+5 = 8
H. 2 is the only even prime number.
Ans. True.
I. All even numbers are composite numbers.
Ans. False.
Since 2 is a prime number.
J. The product of two even numbers is always even.
Ans. True. The product of two even numbers is always even.
Example : 2×4 = 8,
4×6 =24
Q.3. The numbers 13 and 31 are prime numbers. Both these numbers have same digits 1 and 3. FInd such pairs of prime numbers upto 100.
Ans. Such pairs of prime numbers upto 100 are as:
17 and 71
37 and 73
79 and 97
Q.4 Write down separately the prime and composite numbers less than 20.
Ans. Prime numbers less than 20 are as:
2, 3, 5, 7, 11, 13, 17, 19etc.
Composite numbers less than 20 are as:
4, 6, 8, 9, 10, 12, 14, 15, 16, 18 etc.
Q.5. What is the greatest prime number between 1 and 10?
Ans. 7 is the greatest prime number between 1 and 10.
Q. 6. Express the following as the sum of two odd primes.
A. 44
Ans. 44 = 3 + 41
B. 36.
Ans. 36 = 5 + 31
C. 24
Ans. 24 = 5 + 19
D. 18
Ans. 18 = 5 + 13
Q.7 Give three pairs of prime numbers whose differences is 2.
Ans. three pairs of prime numbers whose differences is 2 are as:
3, 5
5, 7
11, 13
Q.8. Which of the following numbers are prime?
A. 23
Ans.
1 × 23 = 23
23 × 1 = 23
Therefore, 23 has only two factors 1 and 23.
Hence, it is a prime number.
B. 51
Ans.
1 × 51 = 51
3 × 17 = 51
Therefore, 51 has four factors 1, 3, 17 and 51.
Hence, it is not a prime number, it is a composite number.
C. 37
Ans.
1 × 37 = 37
37 × 1 = 37
Therefore, 37 has two factors 1 and 37.
Hence, it is a prime number.
D. 26
Ans.
1 × 26 = 26
2 × 13 = 26
Therefore, 26 has four factors 1, 2, 13 and 26.
Hence, it is not a prime number, it is a composite number
Q.9. Write seven consecutive composite number less than 100 so that there is no prime number between them.
Ans. Seven consecutive composite number less than 100 so that there is no prime number between them are as:
90 = 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90
91 = 1, 7, 13, 91
92 = 1, 2, 4, 23, 46, 92
93 = 1, 3, 31, 93
94 = 1, 2, 47, 94
95 = 1, 5, 19, 95
96 = 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96
Q. 10. Express each of the following numbers as the sum of three odd primes.
A. 21
Ans. 21 = 3 + 5 + 13
B. 31
Ans. 31 = 3 + 5 + 23
C. 53
Ans. 53 = 13 + 17 + 23
D. 61
Ans. 61 = 7 + 13 + 41
Q. 11. Write five pairs of prime numbers less than 20 whose sum is divisible by 5.
Ans. FIve pairs of prime numbers less than 20 whose sum is divisible by 5 are as:
2, 3
2, 13
17, 3
7, 13
11, 19
Q. 12. Fill in the blanks:
A. A number which has only two factors is called a _________________.
Ans. Prime number.
B. A number which has more than two factors is called a ___________.
Ans. Composite number.
C. 1 is neither _________ nor _______.
Ans. Prime number, Composite number.
D. The smallest prime number is _________.
Ans. 2.
E. The smallest composite number is _________.
Ans. 4.
F. The smallest even number is _________.
Ans. 2.