CAT 2017 Slot 2 QA Q28 Number Systems

Question 28 of the Quantitative Ability (QA) section, CAT 2017 Slot 2, with CAT's official answer.

How many different pairs (a, b) of positive integers are there such that a ≤ b and \(\frac{1}{a}\) + \(\frac{1}{b}\) = \(\frac{1}{9}\) ? [TITA]

TITA: type in the answer. There are no options and no negative marking.

Answer: 3 Number Systems TITA

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