Question

In the sequence S of numbers, each term after the first two terms is the sum of the two immediately preceding terms. What is the 5th term of S

Answer 1

5th term = 2*1st term + 3*2nd term

Explanation:

z₁ : 1st term, z₂ : 2nd term

z₃ = z₁ + z₂

z₄ = z₃ + z₂ = z₁ + 2*z₂

z₅ = z₄ + z₃ = (z₁ + 2*z₂) + (z₁ + z₂) = 2*z₁ + 3*z₂