math precalculus 12

Question

A helium balloon rises 120m the first minute after it is released, each subsequent minute it rises 3% less than the previous minute. How high is the balloon 10mins after release?

Answer 1

Use the formula for finite geometric series: S_n = t₁(1 - rⁿ)/(1 - r) , where t₁ = 120 and r = .97 and n = 10.