Calculus problem #3: Exponential and Logarithmic Functions. Please Help!!!?

Question

The value of a certain industrial machine is decreasing exponentially. If the machine was originally worth $50,000 and was worth $20,000 when it was 5 years old, how much will it be worth when it is 10 years old?

Answer 1

After 5 years the value is 2/5 of the original amount. So after another 5 years the value will be 2/5 of $20,000, i.e. $4,000.