A number when divided by 5, leaves 3 as a remainder. What will be the remainder when the square of this number is divided by 5.
Correct Answer: 4
Explanation:
Let the number be N.
Therefore N = 5k + 3 On squaring both sides, we get
N2 = ( 5k + 3)2
= 5( 5k2 + 6k +1 ) + 4
∴ On dividing x2 by 5, the remainder is 4
