Acontractor is building the base of a circular fountain. on the blueprint the base of the fountain has a diameter of 18 centimeters. the blueprint has the skill of 3 cm to 4 feet. what will be the actual area of the base of the fountain in square feet after it is built. round your answer to the nearest 10th of a foot square

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.