Elroy enjoys roller skating and weight training. Let X represent the number of hours he spends roller skating weekly, and let Y represent the number of hours he spends weight training weekly. The mean of X is 5 hours, and the mean of Y is 7 hours. Which answer choice correctly calculates and interprets the mean of the sum, S = X + Y?

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.

What fraction is equivalent to 0.46464646··· a. 46⁄999 b. 46⁄100 c. 46⁄99 d. 23⁄50

The area of the map is the product of the length and width. write and expression for the area as the product of the two binomials do not multiply