Zack bought a coat for $69.78. he paid with a $100.00 bill and received $26.73 in change. how much was the sales tax?

The depth of a lake at a certain point, wich is a function of the distance of that point from shore, is 30 feet.

Scott harris can invest $7,000 in a 1-year cd that earns interest at an annual rate of 4 percent compounded monthly. the amount per $1.00 is 1.040742. he can also invest $7,000 in a 1-year cd at annual rate of 4 percent compounded quarterly. the amount per $1.00 is 1.040604. what is the difference in the amount of interest earned for each investment? a) $0.96 b) $0.81 c) $0.87 d) $0.88

Suppose i flip two identical coins. what is the probability that i get one head and one tail?