Q) Prove that 4n can never end with digit 0, where n is a natural number.
Ans:
If the number 4n, for any n, were to end with digit zero, it would be divisible by 5. So, the prime factorization of 4n should contain the prime factor 5.
But in 4n, for any value of n, number will end either with 6 or with 4.
Therefore, there is no natural number n for which 4n ends with digit zero.