MathematicsEasy64×since 2002Q2985The value of r for which ²⁰C_r ²⁰C₀ + ²⁰C_r−-−1 ²⁰C₁ + ²⁰C_r−-−2 ²⁰C₂ + . . . . .+ ²⁰C₀ ²⁰C_r is maximum, isA20B15C10D11Check answerSkip