CAT 2025 Quant was dominated by Algebra followed by Arithmetic. In Arithmetic, the questions were dominated by topics like Speed-time-distance, Mixture and Alligations. This year, there was a surprise. The questions from Geometry were relatively on the lower side as compared to the previous years. There were 8 TITA Qs this year. Overall this section was at a medium level of difficulty.
Question 22 : Let \(3 \leq x \leq 6\) and \(\left[x^2\right]=[x]^2\), where \([x]\) is the greatest integer not exceeding \(x\). If set S represents all feasible values of \(x\), then a possible subset of S is
The condition \(x^2=\lfloor x\rfloor^2\) becomes:
Let \(n=\lfloor x\rfloor\).
\(x^2=n^2\Longleftrightarrow n^2\le x^2<n^2+1\)
Taking square roots:
\(\sqrt{n^2}\le x<\sqrt{n^2+1}\)
\(\Rightarrow n\le x<\sqrt{n^2+1}\)
For \(n=3\) (\(x=3\)):
\(3\le x<\sqrt{3^2+1}\)
\(x\in[3,\sqrt{10})\)
For \(n=4\) (\(x=4\)):
\(4\le x<\sqrt{4^2+1}\)
\(x\in[4,\sqrt{17})\)
For \(n=5\) (\(x=5\)):
\(5\le x<\sqrt{5^2+1}\)
\(x\in[5,\sqrt{26})\)
For \(x=6\):
\(6^2=36=6^2\Rightarrow x=6\)
Complete Feasible Solution Set:
\(S=[3,\sqrt{10})\cup[4,\sqrt{17})\cup[5,\sqrt{26})\cup\{6\}\)
Now as we have the total solution set, we can eliminate the non feasible options which lie outside our solution set.
Therefore options A, B, C are eliminated.
Therefore only D is a subset of out solution set.
The question is " Let \(3 \leq x \leq 6\) and \(\left[x^2\right]=[x]^2\), where \([x]\) is the greatest integer not exceeding \(x\). If set S represents all feasible values of \(x\), then a possible subset of S is "
Choice 4 is the correct answer.
Copyrights © All Rights Reserved by 2IIM.com - A Fermat Education Initiative.
Privacy Policy | Terms & Conditions
CAT® (Common Admission Test) is a registered trademark of the Indian
Institutes of Management. This website is not endorsed or approved by IIMs.
2IIM Online CAT Coaching
A Fermat Education Initiative,
19/43, MG Chakrapani St,
Sathya Garden, Saligramam, Chennai 600 093
Mobile: (91) 99626 48484 / 94459
38484
WhatsApp: WhatsApp Now
Email: info@2iim.com