What distance does the tip of the pendulum travel on the 10th swing ?

Question

The length of the are travelled by the tip of a pendulum on the first swing is 108 and the length of each succeeding swing is three -fourths of the preceding swing . What distance does the tip of the pendulum travel on the 10th swing ?

Answer 1

Using the formula for the sum of a geometric series,

S₁₀ = 108(1 - 0.75¹⁰) / (1 - 0.75)