A certain gas reserve held about 23 billion cubic feet of the gas in 2020 and is being depleted by about 2.7 billion cubic feet each year.

Question

A certain gas reserve held about 23 billion cubic feet of the gas in 2020 and is being depleted by about 2.7 billion cubic feet each year.

(a) Give a linear equation for the remaining gas reserves, R, in terms of t, the number of years since 2020. (Let R be measured in billions of cubic feet.) 

R(t) =  ?

 

(b) In 2025, what will the gas reserves be? (Round your answer to one decimal place.) 

 billion ft³ 

(c) If the rate of depletion doesn't change, in what year will the gas reserve be depleted? (Round your answer down to the nearest year.) 

Answer 1

R(t) = 23 - 2.7t

R(2025) = 23 - 2.7(2025 - 2020)

0 = 23 - 2.7t