When a positive interger k is divided by 5, the remainder is 3. what is the remainder when 3k is divided by 5?

When the positive integer n is divided by 7 ,the remainder is 2 .What is the remainder when 5n is divided by 7?

When N is divided by 4, the remainder is 3. What is the remainder when 2N is divided by 4.

What is the remainder when 7^(81) is divided by 5

The remainder when 3^21 is divided by 5 is

When 'n' is divisible by 5 the remainder is 2. What is the remainder when n^2 is divided by 5 ?

The remainder when the positive integer m is divided by n is r. What is the remainder when 2m is divided by 2n?