Question

can the no. 6n, n being a natural no. , end with digit 5 ? give reasons.

Answer 1

6n=2n x 3n 
For any number ending with 5 the prime factor 5 should be there in its primefactorisation (for eg: 5=5,15=3x5,25=5x5). In all these 5 is a necessary prime number. But 6n has only 2 and 3 as prime factors.So 6n can never end with digit 5 for any natural number n.

Answer 2

Step-by-step explanation:

6n=2n x 3n 

For any number ending with 5 the prime factor 5 should be there in its primefactorisation (for eg: 5=5,15=3x5,25=5x5). In all these 5 is a necessary prime number. But 6n has only 2 and 3 as prime factors.So 6n can never end with digit 5 for any natural number n.