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MathsHardMCQ2023 · 25 Jan Shift 1

Q66.If ar is the coefficient of x10−r in the Binomial expansion of (1 + x)10 , then ∑10r=1 r3( ar−1 2 (1) 4895 (2) 1210 (3) 5445 (4) 3025

What This Question Tests

This question requires recognizing and simplifying a summation involving powers of r and binomial coefficients, which involves properties of binomial coefficients and differentiation/integration techniques or direct identities.

Concepts Tested

Binomial coefficients propertiesSummation involving binomial coefficientsIdentity (1+x)ⁿ = Σ C(n,r) xʳ

Formulas Used

Coefficient of x^(10-r) in (1+x)^10 is C(10, 10-r) = C(10, r)

r * C(n,r) = n * C(n-1, r-1)

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