Question

Coefficient of x¹¹ in the expansion of (1 + x²)⁴ (1 + x³)⁷ (1 + x⁴)¹² is

(A) 1051 

(B) 1106 

(C) 1113 

(D) 1120

Answer 1

Correct option is (C) 1113 

2x₁ + 3x₂ + 4x₃ = 11

Possibilities are (0, 1, 2); (1, 3, 0); (2, 1, 1); (4, 1, 0). 

∴ Required coefficients