CAT 2018 Quant Questions

Let t1, t2,… be real numbers such that t1+t2+…+tn = 2n2+9n+13, for every positive integer n ≥ 2. If tk=103, then k equals

Show Answer
Correct Answer: 24
$t_{1}+t_{2}+\ldots+t_{n}=2 n^{2}+9 n+13 \rightarrow(1)$
$t_{1}+t_{2}+\ldots+\ {tn}-1=2(n-1)^{2}+9(n-1)+13 \rightarrow(2)$
From $(2)-(1),$ we get $t_{n}=\left(2 n^{2}+9 n+13\right)-\left(2(n-1)^{2}\right.$
$+9(n-1)+13 )=4 n+7$
Given $t_{k}=103=>4 k+7=103 \Rightarrow k=24 \quad$

Get one day FREE Trial of CAT online Full course FREE Registration
Also Check: 841+ CAT Quant Questions with Solutions

CAT Quant Online Course

  • 1000+ Practice Problems
  • Detailed Theory of Every Topics
  • Online Live Sessions for Doubt Clearing
  • All Problems with Video Solutions
₹ 2999

CAT 2018 Questions Paper with Solution PDF Download

CAT 2018 Quant Questions with Solutions

CAT 2018 Slot-1

CAT 2018 Slot-2

Back to Main Page

Try CAT 2020 online course for 1 day for FREE

Please provide your details to get FREE Trial of Bodhee Prep's Online CAT Course for one day. We will inform you about the trial on your whatsApp number with the activation code.