### Playing with Numbers-Solutions Ex. 3.1

CBSE Class –VI Mathematics
NCERT Solutions
Chapter 3 Playing With Numbers (Ex. 3.1)

Question 1. Write all the factors of the following numbers:
(a) 24, (b) 15, (c) 21, (d) 27, (e) 12, (f) 20 , (g) 18, (h) 23, (i) 36
Answer: (a) 24 = 1 x 24 = 2 x 12 = 3 x 8 = 4 x 6 = 6 x 4
$\therefore$ Factors of 24 = 1, 2, 3, 4, 6, 12, 24
(b) 15 = 1 x 15 = 3 x 5 = 5 x 3
$\therefore$ Factors of 15 = 1, 3, 5, 15
(c) 21 = 1 x 21 = 3 x 7 = 7 x 3
$\therefore$ Factors of 21 = 1, 3, 7, 21
(d) 27 = 1 x 27 = 3 x 9 = 9 x 3
$\therefore$ Factors of 27 = 1, 3, 9, 27
(e) 12 = 1 x 12 = 2 x 6 = 3 x 4 = 4 x 3
$\therefore$ Factors of 12 = 1, 2, 3, 4, 6, 12
(f) 20 = 1 x 20 = 2 x 10 = 4 x 5 = 5 x 4
$\therefore$ Factors of 20 = 1, 2, 4, 5, 10, 20
(g) 18 = 1 x 18 = 2 x 9 = 3 x 6
$\therefore$ Factors of 18 = 1, 2, 3, 6, 9, 18
(h) 23 = 1 x 23
$\therefore$ Factors of 23 = 1, 23
(i) 36 = 1 x 36 = 2 x 18 = 3 x 12 = 4 x 9 = 6 x 6
$\therefore$ Factors of 36 = 1, 2, 3, 4, 6, 9, 12, 18, 36
Question 2. Write first five multiples of:
(a) 5, (b) 8, (c) 9
(a) 5 x 1 = 5
5 x 2 = 10
5 x 3 = 15
5 x 4 = 20
5 x 5 = 25
$\therefore$ First five multiples of 5 are 5, 10, 15, 20, 25.
(b) 8 x 1 = 8
8 x 2 = 16
8 x 3 = 24
8 x 4 = 32
8 x 5 = 40
$\therefore$ First five multiples of 8 are 8, 16, 24, 32, 40.
(c) 9 x 1 = 9
9 x 2 = 18
9 x 3 = ,27
9 x 4 = 36
9 x 5 = 45
$\therefore$ First five multiples of 9 are 9, 18, 27, 36, 45.
Question 3. Match the items in column 1 with the items in column 2:
 Column 1 Column 2 (i) 35 (a) Multiple of 8 (ii) 15 (b) Multiple of 7 (iii) 16 (c) Multiple of 70 (iv) 420 (d) Factor of 30 (v) 10 (e) Factor of 50
Answer: (i) $\to$ (b), (ii) $\to$ (d), (iii) $\to$ (a), (iv) $\to$ (c), (v) $\to$ (e)
Question 4. Find all the multiples of 9 up to 100.