If (1+x+x²)⁶ⁿ=a₀+a₁x+....then

(a₀+a₃+a₆+.....)=

(a)3^6n-1

(B)3⁶ⁿ⁺¹

(c)3⁶ⁿ-1

(D)3⁶ⁿ⁺¹-1

HI VAIBHAV,

You can do this problem using a short trick,which is used generally to solve objective problems involving n,this will save ur time and u'll get the correct answer.Do onething put n=1/3,so expression becomes (1+x+x²)² =1+2x+3x² +2x³+x⁴ now a₀+a₃=1+2=3...........now solve all the answers for n=1/3 u'll find that option (a)3^6n-1=3 is the correct answer.