How much chlorine is in the pool after 2 days?

Question

Chlorine is frequently used to disinfect swimming pools. The concentration should remain between 1.5 and 2.5 parts per million. on a warm, sunny day, 30% of the chlorine can dissipate into the air or combine with other chemicals. If the initial amount of chlorine is 2.5 parts per million, the function f(x)=2.5(0.7)^x models the amount of chlorine after x days. How much chlorine is in the pool after 2 days?

Answer 1

f(2)=2.5(0.7)^2

f(2)=1.225 parts per million

 

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