(a) 20 and 28

(b) 15 and 25

(c) 35 and 50

(d) 56 and 120

Answer :

(a) 20 and 28

Factors of 20 are 1, 2, 4, 5, 10, 20

Factors of 28 \(\rightarrow \) 1, 2, 4, 7, 28

Hence, the common factors \(\rightarrow \) 1, 2 and 4.

(b) 15 and 25

Factors of 15 \(\rightarrow \) 1, 3, 5, 15

Factors of 25 \(\rightarrow \)1, 5, 25

Hence, the common factors are 1 and 5.

(c) 35 and 50

Factors of 35 \(\rightarrow \) 1, 5, 7, 35

Factors of 50 \(\rightarrow \) 1, 2, 5, 10, 50

Hence, the common factors are 1 and 5.

(d) 56 and 120

Factors of 56 \(\rightarrow \) 1, 2, 4, 7, 8, 14, 28, 56

Factors of 120 \(\rightarrow\) 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 30, 40, 60, 120

Hence, the common factors are 1,2, 4, and 8.

- Q.2 Find the common factors of: (a) 4, 8 and 12 (b) 5, 15 and 25
- Q.3 Find first three common multiples of: (a) 6 and 8 (b) 12 and 18
- Q.4 Write all the numbers less than 100 which are common multiples of 3 and 4.
- 5. Which of the following numbers are co-prime? (a) 18 and 35 (b) 15 and 37 (c) 30 and 415 (d) 17 and 68 (e) 216 and 215 (f) 81 and 16
- Q.6. A number is divisible by both 5 and 12. By which other number will that number be always divisible?
- Q.7. A number is divisible by 12. By what other numbers will that number be divisible?

- NCERT solutions for class 6 maths chapter 1 Knowing Our Numbers
- NCERT solutions for class 6 maths chapter 2 Whole Numbers
- NCERT solutions for class 6 maths chapter 3 Playing with Numbers
- NCERT solutions for class 6 maths chapter 4 Basic Geometrical Ideas
- NCERT solutions for class 6 maths chapter 5 Understanding Elementary Shapes
- NCERT solutions for class 6 maths chapter 6 Integers
- NCERT solutions for class 6 maths chapter 7 Fractions
- NCERT solutions for class 6 maths chapter 8 Decimals
- NCERT solutions for class 6 maths chapter 9 Data Handling
- NCERT solutions for class 6 maths chapter 10 Mensuration
- NCERT solutions for class 6 maths chapter 11 Algebra
- NCERT solutions for class 6 maths chapter 12 Ratio and Proportion
- NCERT solutions for class 6 maths chapter 13 Symmetry
- NCERT solutions for class 6 maths chapter 14 Practical Geometry

- NCERT solutions for class 6 science chapter 1 Food: Where Does It Come From?
- NCERT solutions for class 6 science chapter 2 Components of Food
- NCERT solutions for class 6 science chapter 3 Fibre to Fabric
- NCERT solutions for class 6 science chapter 4 Sorting Materials into Groups
- NCERT solutions for class 6 science chapter 5 Separation of Substances
- NCERT solutions for class 6 science chapter 6 Changes Around us
- NCERT solutions for class 6 science chapter 7 Getting to Know Plants
- NCERT solutions for class 6 science chapter 8 Body Movements
- NCERT solutions for class 6 science chapter 9 The Living Organisms — Characteristics and Habitats
- NCERT solutions for class 6 science chapter 10 Motion and Measurement of Distances
- NCERT solutions for class 6 science chapter 11 Light, Shadows and Reflections
- NCERT solutions for class 6 science chapter 12 Electricity and Circuits
- NCERT solutions for class 6 science chapter 13 Fun with Magnets
- NCERT solutions for class 6 science chapter 14 Water
- NCERT solutions for class 6 science chapter 15 Air Around us