JEE Main 2019 — Binomial Theorem Question with Solution
From: JEE Main 2019 (Online) 12th April Morning Slot
Question
The coefficient of x18 in the product
(1 + x) (1 – x)10 (1 + x + x2)9 is :
(1 + x) (1 – x)10 (1 + x + x2)9 is :
Choose an option
Show full solutionCorrect option: D
Correct answer
D84
Step-by-step explanation
Coefficient of x18 in (1 + x) (1 - x)10 (1 + x + x2)9
Coefficient of x18 in {(1 - x) (1 - x2) (1 + x + x2)}9
Coefficient of x18 in (1 - x2) (1 - x3)9
9C6 - 0 = 84
Coefficient of x18 in {(1 - x) (1 - x2) (1 + x + x2)}9
Coefficient of x18 in (1 - x2) (1 - x3)9
9C6 - 0 = 84
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This is a previous-year question from JEE Main 2019, 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.