Question

For any natural number n, \( 5^n \) ends with the digit :

• A. 0
• B. 5
• C. 3
• D. 2

Hint:

Numbers ending in 0, 1, 5, or 6 always have the same digit at the units place for any natural power \( n \).

Answer 1

The Correct Option is B

To determine the last digit of \(5^n\) for any natural number \(n\), let's analyze the pattern formed by the powers of 5. Since the focus is on the unit digit, we need to evaluate the unit digits of successive powers of 5:

• For \(n = 1\), \( 5^1 = 5 \). The last digit is 5.
• For \(n = 2\), \( 5^2 = 25 \). The last digit is 5.
• For \(n = 3\), \( 5^3 = 125 \). The last digit is 5.
• For \(n = 4\), \( 5^4 = 625 \). The last digit is 5.

Observing the above examples, it becomes evident that the last digit of \(5^n\) remains 5, irrespective of the value of \(n\). Therefore, we can deduce that:

Conclusion: For any natural number \(n\), the last digit of \(5^n\) is always 5.

Hence, the correct answer is: 5.