An elevator company installs elevators in new buildings. The number of meters of cable needed for an elevator is 12 times the number of stories in the building plus an extra 15 meters needed
to go into the machinery. Which of the following functions best describes how many meters of
cable are needed to install the elevator if there are s stories in the building?

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.