JEE Main 2020MathematicsBinomial TheoremEasyMCQ

JEE Main 2020 — Binomial Theorem Question with Solution

JEE Main 2020 (07 Jan Shift 2)

Question

The number of ordered pairs r,k for which 6.Cr35=k2-3.Cr+136, where k is an integer is

Choose an option

Show full solutionCorrect option: D
Correct answer
D4

Step-by-step explanation

Given, 6.Cr35=k2-3.Cr+136

⇒36r+1×35Crk2-3=6×35Cr, using properties of binomial coefficient.
⇒k2-3=r+16

⇒k2=3+r+16

r can be 5,35

For r=5,k=±2

r=35,k=±3

Hence, number of solution =4

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About this question

This is a previous-year question from JEE Main 2020, covering the Binomial Theorem chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.