Two sporting goods stores are having discount sales on basketballs. • at one store, a basketball is on sale for 20% off the regular price of $24.95. • at the other store, the same kind of basketball is on sale for 25% off the regular price of $25.80. what is the difference between the sale prices of the two stores? show how u got the answer plz

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.