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?

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Accepted Answer

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.

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?

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