If $4$ is written $4444$ times side by side, we shall get a number of $4444$ digits. What is the remainder when $7$ divides this large number?
Answer of this question is $1$ but I did not understand how?
Using this rule I tried solving the question, If P is a prime number>5 then any digit written (N-1) times will be divisible by P where N is a recurring decimal. Number of times digit gets repeated in $1/7$ is $6$