Question

EXERCISE - 1.2
1. Express each of the following numbers as a product of its prime factors
(1) 140
(ii) 156
(mm) 3825
(iv) 5005
(v) 7429
2. Find the LCM and HCF of the following integers by the prime factormation method
() 12, 15 and 21
(m) 17.23, and 29
(W) 8, 9 and 25
(iv) 72 and 108
(v) 306 and 657
3. Check whether 6" can end with the digito for any natural number
4. Explain why 7 x 11 x 13+ 13 and 7 x 6 x 5 x 4 x 3 x 2x1 +5 are composite
numbers
5. How will you show that (17 x 11 x 2) + (17 x 11 x 5) is a composite number
Explain
6. What is the last digit of 6​

Answer 1

Answer:

1. Express each of the following numbers as a product of its prime factors

(1) 140

(ii) 156

(mm) 3825

(iv) 5005

(v) 7429

2. Find the LCM and HCF of the following integers by the prime factormation method

() 12, 15 and 21

(m) 17.23, and 29

(W) 8, 9 and 25

(iv) 72 and 108

(v) 306 and 657

3. Check whether 6" can end with the digito for any natural number

4. Explain why 7 x 11 x 13+ 13 and 7 x 6 x 5 x 4 x 3 x 2x1 +5 are composite

numbers1. Express each of the following numbers as a product of its prime factors

(1) 140

(ii) 156

(mm) 3825

(iv) 5005

(v) 7429

2. Find the LCM and HCF of the following integers by the prime factormation method

() 12, 15 and 21

(m) 17.23, and 29

(W) 8, 9 and 25

(iv) 72 and 108

(v) 306 and 657

3. Check whether 6" can end with the digito for any natural number

4. Explain why 7 x 11 x 13+ 13 and 7 x 6 x 5 x 4 x 3 x 2x1 +5 are composite

numbers