Question

In 2005, a Nevada silver mine exported 200 tons of silver. In 2008, as the silver supply became exhausted, it only exported 25 tons of silver. What is the rate of change of the mine’s silver output? A. -175/3. B. -1/50. C. 175/3. D. 75

Answer 1

The rate of change in the amount of silver supplied is equal to the ratio of the difference in the amount supplied to the number of years elapsed from 2005 to 2008. That is,
               rate of change = (25 - 200) / (2008 - 2005) = -173/3
The answer is letter A. 

Answer 2

Answer:

The correct answer is option A.

Explanation:

Amount of silver exported in 2005 = 200 tons

Amount of silver exported in 2008 = 25 tons

Rate of change of silver output:

$\frac{\text{Silver exported in 2008}-\text{Silver exported in 2005-}}{\text{time elapsed}}=\frac{25-200}{2008-2005}=\frac{-175}{3}$

Hence, the correct answer is option A.