AP State Syllabus AP Board 6th Class Maths Solutions Chapter 3 HCF and LCM Ex 3.3 Textbook Questions and Answers.
AP State Syllabus 6th Class Maths Solutions 3rd Lesson HCF and LCM Ex 3.3
Question 1.
Write all the factors for the following numbers.
(i) 24 (ii) 56 (iii) 80 (iv) 98
Answer:
i) 24
24 = 1 × 24
24 = 3 × 8
24 = 2 × 12
24 = 4 × 6
Factors of 24 are 1,2, 3, 4, 6, 8, 12 and 24.
ii) 56
56 = 1 × 56
56 = 7 × 8
56 = 2 × 28
56 = 4 × 14
Factors of 56 are 1, 2, 4, 7, 8, 14, 28 and 56.
iii)80
80 = 5 × 16
80 = 2 × 40
80 = 8 × 10
80 = 4 × 20
Factors of 80 are 1, 2, 4, 5, 8, 10, 16, 20, 40 and 80.
iv) 98
98 = 7 × 14
98 = 2 × 49
Factors of 98 are 1, 2, 7, 14, 49, 98.
Question 2.
What is the greatest prime number between 50 and 100
Answer:
The greatest prime number between 50 and 100 is 97.
Question 3.
The numbers 13 and 31 are prime numbers. Both these numbers have same digits 1 and 3. Find 2 more such pairs of prime numbers below 100.
Answer:
17 and 71; 37 and 73; 79 and 97.
Question 4.
Express the following numbers as the sum of two odd primes.
(i) 18 (ii) 24 (iii) 36 (iv) 44
Answer:
i) 18 = 7 + 11 = 5 + 13
ii) 24 = 5 + 19 = 7 + 17 = 11 + 13
iii) 36 = 5 + 31 = 7 + 29 = 13 + 23 = 47 + 19
iv) 44 = 3 + 41 = 7 + 37 = 13 + 31
Question 5.
Write seven consecutive composite numbers less than 100.
Answer:
Consecutive composite numbers are 8, 9; 9, 10; 14, 15; 15, 16; 20, 21; 21, 22; 24, 25; 25, 26; 26, 27; 27, 28; 32, 33; 33, 34; 34, 35; 35, 36;…….
Question 6.
Write two prime numbers whose difference is 10.
Answer:
Two prime numbers whose difference is 10 are (7, 17); (13, 23); (31, 41); (43, 53); (61, 71); (79, 89);…….
Question 7.
Write three pairs of prime numbers less than 20, whose sum is divisible by 5.
Answer:
| Pair of primes | Sum | Is divisible by 5 or not ? |
| 2,3 | 2 + 3 = 5 | Yes |
| 3,7 | 3 + 7 = 10 | Yes |
| 7, 13 | 7 + 13 = 20 | Yes |