Page 52 - Maths Class 05

Example : List all the factors of 48 and 11.

Solution : Factors of 48 Factors of 11

48 = 1 × 48 11 = 1 × 11

2 × 24 \ The factors of 11 are 1 and 11.

3 × 16
4 × 12

6 × 8
\ The factors of 48 are 1, 2, 3, 4, 6, 8, 12, 16, 24 and 48.

From the above example, it is clear that :

« Every number has at least two factors 1 and the number itself.

« All the factors of a number are less than or equal to the number, not greater than it.

Common Factors

Example : Find the common factors of 10, 15 and 20.

Solution : The given numbers are 10, 15 and 20.

1 × 10 = 10, 2 × 5 = 10

All the factors of 10 are 2, and 10.1 5

1 × 15 = 15, 3 × 5 = 15

All the factors of 15 are , 3, and 15.1 5

1 × 20 = 20, 2 × 10 = 20, 4 × 5 = 20

All the factors of 20 are , 2, 4, , 10 and 20.1 5

The numbers 1 and 5 appear in all the three lists of factors.

Hence, common factors of 10, 15 and 20 are 1 and 5.

Practice - 3.3
Practice - 3.3
Practice - 3.3
Practice - 3.3
1. Find the factors of 18.
2. Find the factors of 20.

3. Find the factors of 10.
4. Find the common factors of.

a. 12 and 16 b. 32 and 40 c. 65, 75 and 81 d. 90, 105 and 125

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