Respuesta :
Answer: first option, Every foot of pipe removes 20% of the pollulant.
Explanation:
20% removal means that after passing every foot of clay pipe, 80% of pollulant remains = 80/100 = 0.8
Then the amount of pollulant left in the fuel after passing x feet will be A*0.8^x
f(x) = 10(0.8)^x
Initial amount, A => x = 0 => f(0) = 10 = A
After one foot: 10 - 0.2(10) = 10*0.8
After two feet: 10*0.8 - 10*0.8*0.2 = 10*0.8[1-0.2] = 10*0.8*0.8 = 10*0.8^2
After three feet: 10*0.8^3
After n passes: 10*0.8^n
Explanation:
20% removal means that after passing every foot of clay pipe, 80% of pollulant remains = 80/100 = 0.8
Then the amount of pollulant left in the fuel after passing x feet will be A*0.8^x
f(x) = 10(0.8)^x
Initial amount, A => x = 0 => f(0) = 10 = A
After one foot: 10 - 0.2(10) = 10*0.8
After two feet: 10*0.8 - 10*0.8*0.2 = 10*0.8[1-0.2] = 10*0.8*0.8 = 10*0.8^2
After three feet: 10*0.8^3
After n passes: 10*0.8^n
Answer:
Every foot of the pipe keeps 80% of the pollutant.
Explanation:
Took the test, trust me