Practice Questions

A = { x : x = vowels in the word PRINCIPLE}

A = { I, E}

A = { x : x is a perfect square ; x< 50}

x is a perfect square ; x²< 50

⇒ x = 1, 2, 3, 4, 5, 6, 7

A = {1, 2, 3, 4, 5, 6, 7}

A = { x : x is a perfect number ; x < 40}


 A = {6, 28}

a perfect number is a positive integer that is equal to the sum of its positive proper divisors, that is, divisors excluding the number itself.

x² + x - 2 = 0

(x + 2)(x -1) = 0

x = - 2 or +1

the set of solution for the equation x² + x - 2 = 0

A = { -2, 1}

prime numbers less than are 2 , 3 , 5 , 7 .

 set of all prime numbers less than 10 = {2, 3, 5, 7}

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