13. Finance The formula for simple interest is I = prt, where I is the interest, p is the principal, r is the interest rate per year, and t is the time in years.
a. You invest $550 for three years. Find the amount of simple interest you earn
with an annual interest rate of 4.5%.
b. Suppose you invested $900 for two years. You earned $67.50 in simple
interest. What was the annual rate of interest?
c. You invest $812 with an annual interest rate of 6.5%. You earned $316.68 in
simple interest. For how many years was the money invested?

Which are factor pairs of 350? choose all answers that are correct. a) 30 and 12 b) 35 and 10 c) 70 and 5 d) 2 and 125

A50% increase followed by 33 1/2% decrease

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.