Is N divisible by 7?

Number Theory Level 2

Let $N = 999\ 980\ 317$ . Is $N$ divisible by $7$ ?

Cannot be determined Yes No

1 solution

Saee Patil
Mar 3, 2019

Note that N={10}^9-{3}^9 =(10-3)(some number k)=7k Hence N is a multiple of 7. You can even check directly by dividing N by 7.