Need help please show the change to multiplication and then answer.

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.

What is the surface area of the sphere?

2.12 school absences. data collected at elementary schools in dekalb county, ga suggest that each year roughly 25% of students miss exactly one day of school, 15% miss 2 days, and 28% miss 3 or more days due to sickness.61 (a) what is the probability that a student chosen at random doesn’t miss any days of school due to sickness this year? (b) what is the probability that a student chosen at random misses no more than one day? (c) what is the probability that a student chosen at random misses at least one day? (d) if a parent has two kids at a dekalb county elementary school, what is the probability that neither kid will miss any school? note any assumption you must make to answer this question. (e) if a parent has two kids at a dekalb county elementary school, what is the probability that both kids will miss some school, i.e. at least one day? note any assumption you make.