IGCSE Math chapter 9 (E)

In the cinema with a capacity of 1,656 people is 105 seats in the last row. How many rows are in the cinema, if in each lower row is always 3 seats less than in the previous row ?

Find the term a₆ of the geometric sequence if you know a₉ = 1,024 and r = 2

Find the term a₈ of the geometric sequence if you know a₅ = 48 and a₆ = 96

Find the terms a₈ of the geometric sequence if you know a₄ - a₂ = 8 and a₂ + a₃ = 4