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oooo T-Mobile LTE 12:04 AM courses.apexlearning.com onential and Logarithmic Functions SUBMIT Question 5 of 25 Multiple Choice: Please select the best answer and click submit. The price of 9-volt batteries is increasing according to the function below, where t is years after January 1, 1980. During what year will the price reach $5? PtO 1.1.80.047t O A 2012 OB. 2008 O c. 2004 P() 1.1 e0.047t D. 2016 Pa

Solution

P( t ) = 1.1*e^0.047t . When the price of the 9 volt battery is $ 5, we have 1.1*e^0.047t = 5 or, e^0.047t = 5/1.1 . On taking natural logariths of both sides, we have, 0.047 t = ln (5/1.1) = ln(4.545454545) = 1.514127733. Therefore, t = 1.514127733./0.047 =32.215 . Since, t is counted from 1980, The price of the 9 volt battery will become $ 5 in 1980 + 32.215 or, in 2012.The answer is A.