In which group would one friend get the most money ? group a: 2 friends share 24 dollars evenly group b: 3 friends share 27 dollars evenly group c: 4 friends share 36 dollars evenly write an equation for the group whose friends get the most money:

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.