Question

Assertion (A): The number \[5^{n}\] cannot end with digit 0, where n is a natural number.

Reason (R): Prime factorisation of 5 has only two prime factors 1 and 5.

Options

• Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).

• Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).

• Assertion (A) is true and Reason (R) is false.

• Assertion (A) is false and Reason (R) is true.

Answer 1

Assertion (A) is true and Reason (R) is false.

Explanation:

Step 1 – Assertion: A is true. A number ending in 0 must have both 2 and 5 as prime factors, but \[5^{n}\] has no factor 2; hence, it cannot end in 0.

Step 2 – Reason: R is false. The prime factorisation of 5 is 5; 1 is not a prime number.