Question

The remainder when 3^21 is divided by 5 is??
With explanation pls.....

Answer 1

its remainder is 3 because after 4th power it's last digits is repeat and due to which last digits of 21th power of 3 is 3 so remaider is 3

Answer 2

Answer:

Step-by-step explanation:

If the powers of a number is a term in this A.P.1,5,9,13,17,21,.........the unit digit repeats. Here the power is a term in this A.P.So remainder is 3.