Question

To find the prime factors of a given number, we have to divide the given number by possible prime number.

• A. largest
• B. smallest
• C. 1

Answer 1

The correct option is B smallest

To find the prime factors of a given number, we divide the number by the smallest prime number 2.

If it is not divisible by 2, then, we divide the number by the prime number greater than 2 i.e. 3 and so on.

For example, let's find the prime factors of 420 using factor tree method.



Step 1: We keep on dividing the number by 2 until the new quotient is not divisible 2.

Finally, we obtain 105

Step 2: We keep dividing the number by 3 until the new quotient is not divisible 3.

$\Rightarrow$ We obtain 35

Step 3: We keep dividing the number by the next prime number, i.e., 5, until the new quotient is not divisible 5.

$\Rightarrow$ We obtain 7 as quotient, which is itself a prime number.