NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 1: Number System - Multiple Choice Questions
Question 28

Question.  28

The number of distinct prime factors of the smallest 5-digit number is

(A)

2

(B)

4

(C)

6

(D)

8

Detailed Answer with Explanation:

Step 1: The smallest 5-digit number is 10000.

Step 2: Write it using powers of 10: \(10000 = 10^4\).

Step 3: Factor 10 into primes: \(10 = 2 \times 5\).

Step 4: Substitute into \(10^4\): \(10^4 = (2 \times 5)^4\).

Step 5: Expand the power: \((2 \times 5)^4 = 2^4 \times 5^4\).

Step 6: The prime factors here are 2 and 5. They are different, so they are distinct.

Therefore, the number of distinct prime factors = 2.

NCERT Exemplar Solutions Class 6 – Mathematics – Unit 1: Number System – Multiple Choice Questions | Detailed Answers