The cooking club made some pies to sell
at a basketball game to raise money for the
new math books. the cafeteria
contributed four pies to the sale. each pie
was then cut into seven pieces and sold.
there were a total of 63 pieces to sell.
how many pies did the club make?

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.