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MathsMediumNumerical2022 · 28 Jun Shift 1

Q87.Let R1 and R2 be relations on the set {1, 2, … , 50} such that R1 ={ (p, pn) : p is a prime and n ≥0 is an integer} and R2 ={ (p, pn) : p is a prime and n = 0 or 1 }. Then, the number of elements in R1 −R2 is ____.

What This Question Tests

This question assesses the understanding of defining relations based on specific conditions involving prime numbers and integers, and then finding the number of elements in their set difference.

Concepts Tested

Definition of a setPrime numbersSet difference (R1 - R2)Counting elements in a set

Formulas Used

Set difference: A - B = {x | x ∈ A and x ∉ B}

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