A deep-sea diver is in search of coral reefs. He finds a beautiful one at an elevation of feet. While taking pictures of the reef, he catches sight of a manta ray. He swims up feet to check it out. What is the diver's new elevation? A. -146 feet B. feet C. feet D. 146 feet

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.