Ans: (c)

The terms of the given sequence are as follows :

a₁ = 81.33       a₇ = a₁

a₂ = -19           a₈ = a₂

a₃ = a₂ – a₁       a₉ = a₃

a₄ = - a₁             a₁₀ = a₄ = -a₁

a₅ = -a₂               a₁₁ = a₄ = - a₂

a₆ = - a₂ + a₁    a₁₂ = a₆ = -a₃ and so on.

The sum of the first six terms, the next six terms and so on is 0.

The sum of the first 6002 terms can be written as the sum of first 6000 terms + 6001^st term + 6002^nd term. From the above explanation, the sum of the first 6000 terms is zero, 6001 term will be a1 and 6002^nd term will be a₂. The sum of the first 6002 terms will be a₁ + a₂ = 81.33 + (-19) = 62.33.