Please answer quickly , i have my math exam tomorrow....

5ⁿ doesnot end with the digit 0 for any value of n.

This is because the only prime in the factorisation of 5ⁿ  is 5.

 

So, the uniqueness of the Fundamental Theorem of Arithmetic guarantees that there are no

other primes in the factorisation of 5ⁿ.

So, there is no natural number n for which 5ⁿ ends with the digit zero.