SOLUTION: The rate of inflation is such that the price of a car costing $20,000 will double in eight years. What will be the price of the car in 5 years?

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: The rate of inflation is such that the price of a car costing $20,000 will double in eight years. What will be the price of the car in 5 years?      Log On


   

Question 1029330: The rate of inflation is such that the price of a car costing $20,000 will double in eight years. What will be the price of the car in 5 years?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +r+ = the rate of inflation
+40000+=+20000%2A%28+1+%2B+r+%29%5E8+
+%28+1+%2B+r+%29%5E8+=+2+
Take the log of both sides
+8%2Alog%28+1+%2B+r+%29+=+log%282%29+
+log%28+1+%2B+r+%29+=+log%282%29+%2F+8+
+log%28+1+%2B+r+%29+=+.30103%2F8+
+log%28+1+%2B+r+%29+=+.03763+
+1+%2B+r+=+10%5E.03763+
+1+%2B+r+=+1.0905+
+r=+.0905+
----------------
Let +p+ = the price of the car in 5 years
+p+=+20000%2A%28+1.0905+%29%5E5+
+p+=+20000%2A1.5422+
+p+=+30843.12+
The price will be $30,843.12 in 5 yrs