Question bank/JEE Main/Mathematics

JEE MainMathematicsModerateBinomial Theorem

Let n be an odd integer and the number (n 151 )(n\ 151\ ) is divisible
by
(n 150 )(n\ 150\ ) but is not equal to it. Then the half of sum of the
digits of smallest value of is (where
(n r ) (n\ r\ )\ denotes
 nCr\ ^{n}C_{r})

Show answer and solution
Let [IMAGE] where q≠1q \neq 1
[IMAGE] or n = 150q + 150

Smallest n will be when q = 3 (n should be odd)

n = 453 + 150

n = 603
⇒\Rightarrow sum of the digit = 9


Source: Grass-G / M-08 Mathematics Paper 23 October.docx

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