Page 185 - New Medley 4 Semester 1

Example 2: Find the factors of 13.

Solution: 13 = 1 × 13

There are no numbers other than 1 and 13 that can divide
13 completely.

\ 1 and 13 are the two factors of 13.

Common Factors

First, we find all the factors of the given numbers and then sort out the

factors that are common.

Example 3: Find the common factors of 32 and 12.

Solution: Factors of 32: 1, 2, 4, 8, 16, 32

Factors of 12: 1, 2, 3, 4, 6, 12

\ Common factors of 32 and 12 are 1, 2 and 4.

Also, we can show this in a diagram given below:

16 1 3
Factors of 32 → 2 6 ← Factors of 12
32 4
12
↑

Common factors of 32 and 12

EXERCISE 5.1

A. Write all the factors of the following numbers.
1. 12 2. 18 3. 25 4. 35

5. 40 6. 60 7. 72 8. 90

B. In each of the following, check whether the first number is a factor of

the second one.
1. 9, 72 2. 11, 143 3. 20, 275 4. 16, 1728

5. 9, 639 6. 11, 5620 7. 18, 8658 8. 19, 1245

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