A number when divided by 5 leaves a remainder 3. What is

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A number when divided by 5 leaves a remainder 3. What is the remainder when the square of the same number is divided by 5 ?

1. 9
2. 3
3. 1
4. 4

Correct Option: D

The number is of the form (5x + 3 ) where x is an integer

∴ [(5x + 3)²] / 5 = ( 25x² + 30x + 9) / 5
= 25x²/ 5 + 30x/5 + (5 +4)/5
∴ The remainder is 4.