HCF and LCM Class 7 Practice Set 10 Answers Solutions Chapter 3
Question 1
Maharashtra Board Solution
Which number is neither a prime number nor a composite number?
Solution & Step-by-Step Answer:
1
Question 2
Maharashtra Board Solution
Which of the following are pairs of co-primes? i. 8,14 ii. 4,5 iii. 17,19 iv. 27,15
Solution & Step-by-Step Answer:
i. Factors of 8: 1, 2, 4, 8 Factors of 14: 1, 2, 7, 14 ∴ Common factors of 8 and 14: 1,2 ∴ 8 and 14 are not a pair of co-prime numbers.
ii. Factors of 4: 1, 4
Factors of 5: 1, 5
∴ Common factors of 4 and 5: 1
∴ 4 and 5 are a pair of co-prime numbers.
iii. Factors of 17: 1, 17
Factors of 19: 1, 19
∴ Common factors of 17 and 19: 1
∴ 17 and 19 are a pair of co-prime numbers.
iv. Factors of 27: 1, 3, 9, 27
Factors of 15: 1, 3, 5, 15.
∴ Common factors of 27 and 15 : 1,3
∴ 27 and 15 are not a pair of co-prime numbers.
Question 3
Maharashtra Board Solution
List the prime numbers from 25 to 100 and say how many they are.
Solution & Step-by-Step Answer:
29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97. There are 16 prime numbers from 25 to 100.
Question 4
Maharashtra Board Solution
Write all the twin prime numbers from 51 to 100.
Solution & Step-by-Step Answer:
Question 5
Maharashtra Board Solution
Write 5 pairs of twin prime numbers from 1 to 50.
Solution & Step-by-Step Answer:
Question 6
Maharashtra Board Solution
Which are the even prime numbers?
Solution & Step-by-Step Answer:
2
Maharashtra Board Class 7 Maths Chapter 3 HCF and LCM Practice Set 10 Intext Questions and Activities
Question 1
Maharashtra Board Solution
Answer the following questions. (Textbook pg. no. 15) i. Which is the smallest prime number? ii. List the prime numbers from 1 to 50. How many are they? iii. Identify the prime numbers in the list below. 17, 15,4, 3, 1, 2, 12, 23, 27, 35, 41, 43, 58, 51, 72, 79, 91, 97.
Solution & Step-by-Step Answer:
i. 2 is the smallest prime number. ii. There are 15 prime numbers from 1 to 50. They are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47. iii. [17], 15,4, [3], 1, [2], 12, [23], 27, 35, [41], [43], 58, 51, 72, [79], 91, [97].