Virginia starts with 200
milligrams of a radioactive substance. The amount of the substance decreases by 25%
each week for a number of weeks, w
. The expression 200(1−0.25)^w
finds the amount of radioactive substance remaining after w
weeks. Which statement about this expression is true?
CLEAR CHECK
It is the product of the initial amount and the decay factor after w
weeks.
It is the difference between the initial amount and the percent decrease.
It is the difference between the initial amount and the decay factor after w
weeks.
It is the initial amount raised to the decay factor after w
weeks.
The correct statement is:
It is the product of the initial amount and the decay factor after w weeks.