Pam bought several cartons of giggle fruit drinks to sell during the track meet. she paid 50 cents per carton. she sold all but 15 of the cartons for $1 each. at the end of the day, her profit was $22.50. how many cartons of giggle did she buy?

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.