Odpowiedź:
a₁ = 2
a₂ = 5
a₃ = 8
a₄ = 11
r różnica ciągu = a₄ - a₃ =a₃ - a₂ = a₂ - a₁
r = 11 - 8 = 8 - 5 = 5 - 2 = 3
a₃₀ = a₁ + 29r = 2 + 29 * 3 = 2 + 87 = 89
a₂₀₀ = a₁ + 199r = 2 + 199 * 3 = 2 + 597 = 599
S₂₀₀ = (a₁ + a₂₀₀) * 200/2 = (2 + 599) * 100 = 601 * 100 = 60100
