I need help with the 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.

Apackage of five erasers cost 0. $.39 at this rate how many how much would 60 erasers cost in dollars and cents

The table shows the number of hours orlando spent at football practice last week. select the appropriate numbers below to complete the model to find the number of hours orlando spent practicing on tuesday and friday.