Consider the numbers 4n4^n, where nn is a natural number. Check whether there is any value of nn for which 4n4^n ends with the digit zero.

Answer: No, there is no value of nn for which the number 4n4^n ends with the digit zero.

Step-by-step solution

Step 1: Understand the condition for a number to end in zero

For any integer to end with the digit zero, it must be divisible by 10. Since 10=2×510 = 2 \times 5, this means that its prime factorization must contain at least one factor of 2 and at least one factor of 5.

Step 2: Find the prime factorization of the base number

First, we find the prime factorization of the base number, which is 4. The prime factors of 4 are 2×2=222 \times 2 = 2^2. This is a fundamental step as per the Fundamental Theorem of Arithmetic.

Step 3: Express 4n4^n in terms of its prime factors

Now we substitute the prime factorization of 4 into the expression 4n4^n. Using the exponent rule (am)n=amn(a^m)^n = a^{mn}, we find that 4n4^n can be written as 22n2^{2n}. This shows the prime factors of 4n4^n.

Step 4: Analyze the prime factors of 4n4^n

From the expression 22n2^{2n}, it is clear that the only prime factor of 4n4^n is 2. The Fundamental Theorem of Arithmetic states that the prime factorization of any natural number is unique. Therefore, there are no other prime factors present. As per Reference 3, this understanding is critical.

Step 5: Conclusion based on prime factorization

Since the prime factor 5 is not present in the prime factorization of 4n4^n, it cannot be divisible by 5. Consequently, 4n4^n cannot end with the digit zero for any natural number nn, as a number ending in zero must have both 2 and 5 as prime factors. This aligns with the example given in Reference 1 of NCERT Class 10 Mathematics.

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